Using the Map Adjustment Feature{1901, 1902, 7620} Caterpillar

Engine: G3600

Introduction

Do not perform any procedure in this Special Instruction until you have read and understood the information.

This Special Instruction provides instruction on using the "Map Adjustment" feature for G3600 Engines that are equipped with the ADEM III control system.

The "Map Adjustment" feature allows the service technician to make adjustments to certain maps that will allow the engine to perform better under a wider range of site conditions. These conditions include: emissions regulations, ambient temperature, fuel gas quality, altitude and parasitic load during start up.

For example, an engine may have a high parasitic load during starting and difficulty starting under cold conditions. Before making any map adjustments the service technician can log data in Caterpillar Electronic Technician (Cat ET) to determine the reason for the hard starting.

Use the Cat ET Data Logger function to record the following channels: "Engine Speed", "Desired Engine Speed", "Actual Air Pressure", "Desired Air Pressure", "Air to Fuel Differential Pressure", "Actual Air to Fuel Ratio", "Desired Air to Fuel Ratio", "Engine Load Factor", "Percent Fuel Position", "Percent Choke Command" and "Wastegate Position Command".

Record data from the point where the starter engages until the engine reaches low idle or start attempt is aborted.

If actual air to fuel ratio is less than the desired air to fuel ratio then the engine is too rich during the start sequence. The service technician then could go into the "Map Adjustment" feature and raise the "Desired Air to Fuel Ratio" map and the "Transient Air Fuel Ratio Limit" map in the 350 to 700 RPM range. The amount of change will require some trial and error adjustments.

Similar changes to the system can be made to effect emissions, load acceptance, indicated load, and stability. The various operations are covered in the ""Adjusting the Maps Using the Map Adjustment Feature" " section of this instruction.

Engine Maintenance Prior to Using the Map Adjustment Feature

Obtain a gas analysis for the site where the engine is operating. Refer to the Methane Program, LEKQ4196 in order to calculate the lower heating value (LHV).

The following engine maintenance must be performed prior to using the "Map Adjustment" feature:

• Calibrate the Air/Fuel Pressure Module to match site barometric air pressure

• Set the "Fuel Quality Configuration" and "Gas Specific Gravity" to the values of the fuel analysis

• Engine Valve Lash - Inspect/Adjust

• Gas Admission Valve Lash - Inspect/Adjust

• Ignition System Spark Plugs - Clean/Gap or Replace

• Actuator Linkage - Inspect/Adjust

Refer to the engine's Operation and Maintenance Manual for more information.

Refer to any Technical Marketing Data (TMI) that is specific to the engine for emissions information. For example the Test Specifications data, or the Engine Performance Data.

Once the maintenance items that are listed above are completed, run the engine under normal operating load and speed. Verify that there are no misfires. Ensure that the check valves in the prechamber are in proper working condition. Ensure that there are no prechamber coolant leaks.

Note: Do not attempt to use the "Map Adjustment" feature if there are random misfires.

Conduct a normal tune using the "Prechamber Calibration" feature after all engine temperatures have stabilized.

Refer to the engine's Testing and Adjusting, "BTU and Precombustion Chamber Adjustments" for additional information on engine tuning.

Operate the engine at the most commonly used load point and at steady state conditions. Use the example data sheets that are shown in Illustration 1 or in Illustration 2 to collect baseline information on engine performance. If the emissions need adjustment or the indicated load does not match the site intake manifold air specifications, the "Map Adjustment" feature can be used to bring the emissions into compliance and adjust any load offsets.

If the performance problem is related to transient loading, the parameters mentioned (listed above) must be logged while the engine is operating under these conditions. This information should then be communicated to Dealer Solution Network (DSN) for additional assistance in making the appropriate adjustments.

When the engine operation meets site requirements, complete a second data sheet to document the performance changes and list the changes made in the comments section. E-mail all data sheets to the DSN for forwarding to Gas Engine Customer Service. This information will be kept on file to assist with any future performance related problems and documentation of control system changes.

Illustration 1	g01310484
Inline data sheet

Illustration 2	g01310485
Vee data sheet

Software Requirements

Check the personality module part number and build date of the flash file that is installed on the engine. If the software was built prior to October 2006 or is defined as a V1.8, or V1.9, it will not support the "Map Adjustment" feature and will need to be updated.

Install the appropriate G3600 V2.0 (or newer) control system flash file that is specific for the engine rating. The "Map Adjustment" feature was first included in the flash file parts listed in Tables 1, 2, 3, and 4. Files with the build dates after October 2006 will also include this feature, but may not be listed in these tables.

Cat ET version ET2007AV1.2 or a newer version is required to perform the "Map Adjustment" feature.

Table 1

G3606 Flash Files
Version 2.0	App	Comp Ratio	Freq	Rated Power		Rated Speed	SCAC C°	JW C°	Emission Setting (g/bhp-hr NOx	Turbo	Rating Interlock
				bKW	bhp
272-3559	IND	9.2:1		1324	1775	1000	54	88	0.7	TPS57D	1
272-3560
292-9819	IND	9.2:1		1324	1775	1000	54	88	0.5	TPS57D	2
272-3561	EP	9.2:1	60Hz	1191	1597	900	54	88	0.7	TPS57D	3
246-3381
272-3562	IND	9.2:1		1242	1665	1000	54	88	0.7	VTC254	4
272-3601	IND	9.2:1		1344	1803	1000	49	88	< 0.7	TPS57D	5
272-3563
272-3564	IND	9.2:1		1367	1833	1000	43	88	0.7	TPS57D	6
272-3597	IND	9.2:1		1324	1775	1000	54	110	0.7	TPS57D	7
296-0028	IND	9.2:1		1413	1895	1000	32	88	0.7	TPS57D	8

Table 2

G3608 Flash Files
Version 2.0	App	Comp Ratio	Freq	Rated Power		Rated Speed	SCAC C°	JW C°	Emission Setting (g/bhp-hr NOx)	Turbo	Rating Interlock
				bKW	bhp
272-3565	IND	9.2:1		1767	2370	1000	54	88	0.7	VTC254	1
272-3569	IND	9.2:1		1879	2520	1000	32	88	0.7	TPS57D	2
272-3566	IND	9.2:1		1851	2482	1000	38	88	0.7	TPS57D	3
272-3567	IND	9.2:1			2370	1000	54	88	0.7	TPS57D	4
292-9815	IND	9.2:1			2370	1000	54	88	0.5	TPS57D
272-3568	EP	9.2:1	60Hz	1650	2212	900	41	88	0.7	VTC254	5
272-3570	IND	9.2:1		1659	2225	1000	54	88	0.7	VTC254	6
261-7006	EP	9.2:1	60Hz	1589	2130	900	54	110	0.7	TPS57D	7
261-7008	EP LF	9.2:1	60Hz	1589	2130	900	54	110	0.7	TPS57D
286-7869	EP LF	9.2:1	60Hz	1589	2130	900	54	110	0.5	TPS57D	8
292-9816	IND	9.2:1		1823	2445	1000	43	88	0.7	TPS57D	10

Table 3

G3612 Flash Files
Version 2.0	App	Comp Ratio	Freq	Rated Power		Rated Speed	SCAC C°	JW C°	Emission Setting (g/bhp-hr NOx)	Turbo	Rating Interlock
				bKW	bhp
272-3571	IND	9.2:1		2647	3550	1000	54	88	0.7	TPS57D	1
278-0132	IND	9.2:1		2647	3550	1000	54	88	0.5	TPS57D
288-2596	IND	9.2:1		2647	3550	1000	54	88	0.5	TPS57D
272-3572	IND	9.2:1		2822	3785	1000	32	88	0.7	TPS57D	2
288-2598	IND	9.2:1		2822	3785	1000	32	88	0.5	TPS57D
272-3573	IND	9.2:1		2822	3785	1000	32	88	0.5	TPS57D	3
272-3574	EP	9.2:1	60Hz	2371	3180	900	32	88	0.7	VTC254	4
272-3575	IND	9.2:1		2332	3127	1000	58	88	0.7	TPS57D	5
272-3577	IND	9.2:1		2487	3335	1000	54	88	0.7	VTC254	6
295-2928	IND	9.2:1		2288	3068	1000	54	88	0.7	VTC254	6
272-3576	IND	9.2:1		2332	3127	1000	58	88	0.7	TPS57D	7
272-3578	PET	9.2:1		2759	3700	1000	54	88	0.7	VTC254	8
272-3611	IND	9.2:1		2735	3668	1000	43	88	0.7	TPS57D	9
272-3603	EP	9.2:1	50Hz	2632	3530	1000	35	88	0.7	VTC254	10
255-3628	EP	9.2:1	60Hz	2402	3221	900	54	110	0.7	VTC254	11
255-3629	EP	9.2:1	60Hz	2402	3221	900	54	110	0.7	VTC254
255-3630	EP	9.2:1	60Hz	2402	3221	900	54	110	0.7	VTC254

Table 4

G3616 Flash Files
Version 2.0	App	Comp Ratio	Freq	Rated Power		Rated Speed	SCAC C°	JW C°	Emission Setting (g/bhp-hr NOx)	Turbo	Rating Interlock
				bKW	bhp
272-3579	IND	9.2:1		3531	4735	1000	54	88	0.7	VTC254	1
296-4287
272-3580	IND	9.2:1		3315	4445	1000	54	88	0.7	VTC254	3
284-1186	IND	9.2:1		3315	4445	1000	54	88	0.7	VTC254
272-3610	EP	10.5:1	60Hz	3201	4293	900	54/93	99	0.7	VTC254	4
272-3582	EP	9.2:1	60Hz	3176	4259	900	54	110	0.7	VTC254	5
272-3614	EP	10.5:1	50Hz	3807	5105	1000	32/90	99	0.7	VTC254	6
276-0097	EP	10.5:1	50Hz	3788	5080	1000	32/80	99	0.7	VTC254	7
272-3585	IND	9.2:1		3531	4735	1000	54	110	0.7	VTC254	8
292-9820	EP	10.5:1	50Hz	3753	5032	1000	43/93	99	0.5	VTC254	9
276-0098	EP	10.5:1	50Hz	3753	5032	1000	43/93	99	0.5	VTC254
276-0099	IND	9.2:1		3531	4735	1000	54	88	0.7	TPS57D	10
296-0031	IND	9.2:1		3531	4735	1000	54	88	0.7	TPS57D
272-3587	EP	9.2:1	60Hz	3389	4544	900	32	88	0.7	VTC254	11
272-3588	EP	9.2:1	50Hz	3762	5045	1000	32	88	0.7	VTC254	12
282-2063	EP	10.5:1	60Hz	3570	4787	900	32	99	0.7	VTC254	13
278-0137	EP	10.5:1	50Hz	3979	5336	1000	32/93	99	0.5	VTC254	14
272-3590	IND	9.2:1		3762	5045	1000	32	88	0.7	TPS57D	15
292-9821	EP	10.5:1	50Hz	3984	5342	1000	32/93	99	0.7	VTC254	16
272-3593	EP	9.2:1	50Hz	3528	4732	1000	54/83	88	0.7	VTC254	17
236-0996	EP	9.2:1	60Hz	3060	4104	900	54	110	0.5	VTC254	18
272-3594	IND	9.2:1		3531	4735	1000	54	88	0.5	VTC254	19
286-7867	EP	10.5:1	50Hz	3984	5342	1000	32/93	99	0.7	VTC254	20
292-9822	IND	9.2:1		3531	4735	1000	54	88	0.5	TPS57D	21
292-9813	EP	9.2:1	60Hz	3177	4261	900	54	110	0.5	VTC254	22

Using the Map Adjustment Feature

Illustration 3	g01329567
Selecting the "Map Adjustment" feature

Connect Cat ET to the engine's Electronic Control Module (ECM) via the Cat Data Link. Refer to the engine's Troubleshooting guide for information on connecting to the engine's ECM. Once Cat ET is connected to the engine's ECM, select on the menu bar "Service" and then click on "Map Adjustment". This will open the "Map Adjustment" feature. Refer to Illustration 3.

Illustration 4	g01327653
Calibration feedback notification

When modifying the "Desired Air to Fuel Ratio", "Desired Combustion Time", and the "Transient Air Fuel Ratio Limit" maps, the engine must be operating in the "Calibration Feedback" emissions control mode. This is the same engine operation as used in the "Prechamber Calibration" feature. Select the "More..." button to find the "Calibration Feedback Enable/Disable" Toggle button. Refer to the ""More Button" " section for more information.

Illustration 5	g01327610
Selecting the map properties

Selected Map Properties

Click on the down arrow in order to select one of the four maps that are available for adjustment. The maps that can be adjusted are listed below:

• Map 1: Desired Air to Fuel Ratio

• Map 2: Desired Combustion Time

• Map 3: Gas Mass Fuel Flow

• Map 4: Transient Air Fuel Ratio Limit

Illustration 6	g01327558
Map 1: Desired Air to Fuel Ratio

Map 1: Desired Air to Fuel Ratio

The "Desired Air To Fuel Ratio" map determines the air to fuel ratio at any given operating point. This map can be referred to as the master control system map. The "Desired Air To Fuel Ratio" map is only accurate for the condition when the "Fuel Quality Configuration" (BTU) setting is equal to the actual lower heating value (LHV) of the fuel that is supplied to the engine. Therefore, it is important when using the "Desired Air To Fuel Ratio" map adjustment that the "Fuel Quality Configuration" (BTU) setting is equal to the actual fuel quality value.

When the control system is in "Calibration Feedback" mode and in "No Feedback" mode, the engine runs off of the "Desired Air To Fuel Ratio" map. When the control system is in "Combustion Feedback" mode, the engine runs off the "Desired Combustion Time" map. With the control system in "Calibration Feedback" mode, use the "Desired Air To Fuel Ratio" map adjustment to change the NOx emission level.

Increasing the "Desired Air To Fuel Ratio" map will provide a leaner air to fuel mixture and decreases NOx emissions. Decreasing the "Desired Air To Fuel Ratio" map will provide a richer air to fuel mixture and increases NOx emissions.

The maximum "Desired Air To Fuel Ratio" map adjustment range is +/-1 air to fuel ratio and should cover a LHV fuel quality range of approximately 700 to 1100 BTU.

When the control system is in "Calibration Feedback" mode, the "Gas Fuel Correction Factor" will remain at 100 percent. If this is not at 100 percent, then the system is operating in either "Exhaust Temperature Feedback" or "Combustion Feedback" modes, and the system must be placed into "Calibration Feedback" mode to continue the mapping process.

When load acceptance problems are encountered as the engine is warming up, adjustments to the "Desired Air To Fuel Ratio" map can be made to improve load acceptance in that area of the operating speed and load range. Problems accepting load usually indicate the air to fuel ratio is too lean. Richening the air to fuel ratio in the operating range where the engine is having problems accepting load will usually improve transient loading.

Illustration 7	g01327611
Map 2: Desired Combustion Time

Map 2: Desired Combustion Time

For the steady state points above 750 RPM and 50 percent load, the basic goal of engine mapping is to match the emission level when operating in feedback or no feedback conditions. After the "Desired Air To Fuel Ratio" map adjustments have been made that provide the desired NOx emissions when the control system is in "Calibration Feedback" mode, the "Desired Combustion Time" map next needs to be adjusted so the "Desired Combustion Time" matches the actual burn time at the relative operating speed and load points. With the control system in "Calibration Feedback" mode, adjust the "Desired Combustion Time" map at the relevant points to match the "Engine Average Combustion Time" displayed in "Monitored ECM Parameter" section of screen. As a final check to be sure the emissions match when operating on the "Desired Combustion Time" map and the "Desired Air To Fuel Ratio" map, disable the "Calibration Feedback" mode and verify the NOx emissions. Match the emissions in "Calibration Feedback" mode.

Illustration 8	g01327612
Map 3: Gas Mass Fuel Flow

Map 3: Gas Mass Fuel Flow

The "Gas Mass Fuel Flow" map limits the gas mass fuel flow which will limit the maximum torque of the engine. Adjustments to this map will be reflected in the "Engine Load Factor". This map can only be adjusted from 0 to 25 percent downward from the factory map value. This is used for derating the engine so that the "Engine Load Factor" will match the site ratings. To adjust the values of this map, operate the engine at the maximum site rating, then reduce the "Gas Mass Fuel Flow" until the "Engine Load Factor" is 100 percent. The slope of this line must be linear from 675 to 1050 RPM, it is recommended to use the "Data Modify Mode: All Values" to maintain this linearity.

Note: Above 1050 RPM, the "Gas Mass Fuel Flow" map is designed to drop quickly. This is to prevent the engine from overspeed conditions. This must be maintained when making adjustments to this map. Adjust the 1125 RPM point accordingly to maintain approximately the same reduction of fuel as the original map contained.

Illustration 9	g01327613
Map 4: Transient Air Fuel Ratio Limit

Map 4: Transient Air Fuel Ratio Limit

The "Transient Air Fuel Ratio Limit" map limits the fuel control valve position during startup and during transient loading conditions. Without this control, the engine needs excess fuel in order to achieve the desired speed without the capacity to supply enough air due to turbo lag, leading to rich misfire and/or detonation. The "Transient Air Fuel Ratio Limit" map is the floor for the "Desired Air To Fuel Ratio". Therefore, the "Transient Air Fuel Ratio Limit" map must be lower than the "Desired Air To Fuel Ratio" at all points.

Cold starting problems can be encountered when the fuel's LHV is either too rich or is too lean compared to the 905 BTU LHV fuel quality used to develop Caterpillar natural gas engines. For these conditions, the "Transient Air Fuel Ratio Limit" map and the "Desired Air To Fuel Ratio" map will need to be adjusted to achieve acceptable start-up.

The "Desired Air To Fuel Ratio" map defines the ceiling or upper limit of the air to fuel ratio while the "Transient Air Fuel Ratio Limit" map defines the floor or lower limit for the air to fuel ratio. The "Transient Air Fuel Ratio Limit" map has primary control over cold starting and over transient loading between 0 to 700 RPM.

Since the window defined by the "Transient Air Fuel Ratio Limit" map and by the "Desired Air To Fuel Ratio" map (ceiling to floor) should be kept about the same as the factory map, it will be necessary to increase or decrease the "Desired Air To Fuel Ratio" map by the same amount and in the same direction that the "Transient Air Fuel Ratio Limit" map was changed.

The range of adjustment for the "Transient Air Fuel Ratio Limit" map is -1/+5 air to fuel ratios (one air to fuel ratio richer to five air to fuel ratios leaner) from the factory map. This provides sufficient adjustability to handle most starting problems that are encountered when operating on fuel with a LHV of 700 to 1100 BTU.

Note: Always keep the"Transient Air Fuel Ratio Limit" map values below the "Desired Air To Fuel Ratio" map values to prevent engine performance problems.

Illustration 10	g01327615
Map types

Map Type - This feature is used to switch between the map type views which can be displayed: "Base", "Previous", "Current", "Working map" and "File".

Illustration 11	g01327618
Map Type - Base

Map Type - Base - This view shows map values that were loaded from the ECM at the start of the current "Map Adjustment" session. These values will not change for the session, but these values will change between sessions. This is the "Start Over" map. To reset the ECM maps to this version, select the "Copy to Working" button and return to the "Working map" to submit the change.

The "Offset" column will show the difference between the values in the "Base" map with those that are currently operating in the ECM.

Illustration 12	g01327621
Map Type - Previous

Map Type - Previous - This view displays the map values that were operating in the ECM just prior to the last submission. This is the "Go Back" map. To reset the ECM maps to this version of map change, select the "Copy to Working" button and return to the "Working map" to submit the change.

The "Offset" column will show the difference between this map and the current values that are operating in the ECM.

This map will be the same as the "Base" map at the start of the feature and after the first submission. These map values will not change until after a second submission from the "Working map".

Illustration 13	g01327623
Map Type - Current

Map Type - Current - This view displays the values which are currently operating in the ECM. The values in this map will change after each successful submission. In this map, the "Offset" column will show the difference between the "Current" map and the "Working map". Select the "Copy to Working" button to copy the values from this map into the "Working map", if necessary to reset changes to the "Working map" prior to a submission.

Illustration 14	g01327633
Map Type - Working map

Map Type - Working map - This view displays the current map values, the "Valid Range" and the "Modifiable Range" for the selected map. The values in the map can be increased or decreased either as a single point or all points displayed in submission increments up to 0.1 per submission. The changes made in this map are not active in the ECM until the "Submit" button has been selected. Once the submission process is completed, the "Current" map and the "Working map" will display the same values.

This is the only map view where changes can be made and can be submitted to the ECM.

When making map changes it is important to operate the engine at the speed where the changes are required. Then select the axis point which corresponds to the speed. For example, select the "Engine Speed" axis point to 900 RPM if the engine is operating at 900 RPM.

Illustration 15	g01327624
Map Type - File

Map Type - File - This map type is only available after a map has been loaded from a file. To submit this map to the ECM, use the "Copy to Working" button to transfer the data from this map to the "Working map" and submit.

The "Offset" column will show the difference between the "File " map values and those that are currently operating in the engine's ECM.

When loading a "File Map", the Cat ET "Map Adjustment" feature will only accept map files which were created from the same engine sales model and rating as that of the connected ECM. Thus a G3606 file map will not be compatible with a G3616, and G3606 Industrial 0.7 g/bhp-hr NOx is not compatible with a G3606 Industrial 0.5 g/bhp-hr NOx rating. If the map is compatible, then Cat ET will load the map file which is within the "Valid Range" for the ECM maps. When submitting "File Maps" to the ECM, if the changes are significant, the submission should be completed when the engine is not running.

Illustration 16	g01327626
Data Modify Mode

Data Modify Mode

Click on the down arrow in order to change the Data Modify Mode to change between "Single value" or "All values". This enables you to select between being able to change a single value or to change all displayed values.

If you change the "Desired Air to Fuel Ratio" for 1000 RPM and the "Single value" is selected, you will only change the "Desired Air to Fuel Ratio" for 1000 RPM and the selected "Mass Fuel Flow Per Stroke lb/strk" point. If you change the "Desired Air to Fuel Ratio" for 1000 RPM and the "All values" is selected, you will change the "Desired Air to Fuel Ratio" for all the speed points at the selected "Mass Fuel Flow Per Stroke lb/strk". Refer to illustration 15.

Illustration 17	g01327627
Switch Independent Variables

Switch Independent Variables

"Yes" or "No" – Switches the first two columns, map independent axis, so that all points within a given speed range or flow range can be changed at one time.

Click on the down arrow in order to select "Yes" or "No" to the "Switch Independent Variable". This will switch the first two columns of the map selected. If the "Desired Air to Fuel Ratio" is selected and the independent variables are switched by selecting "Yes", the "Engine Speed RPM" and the "Mass Fuel Flow Per Stroke lb/strk" will change in the column order. Refer to Illustration 17 and 18 to see the changes in the column order.

The "Switch Independent Variable" is not available for the"Gas Mass Fuel Flow" map.

Illustration 18	g01327629
Three check boxes

Three Check Boxes

The three check boxes are used to select the information displayed in the top right section of the screen.

Monitored ECM Parameter - When this check box is marked, Cat ET displays eight "Monitored ECM Parameters" to the right of the check box. The "Monitored ECM Parameters" are selected map independent and dependent axis parameters, "Engine Load Factor", "Engine Average Combustion Time" and "Gas Fuel Correction Factor" for all selected maps. Other parameters are included as necessary for each map.

Illustration 19	g01327631
Monitored ECM parameter

The "Monitored ECM Parameter" will change for each map. "Engine Speed", "Engine Load Factor", "Engine Average Combustion Time", and "Gas Fuel Correction Factor" are displayed for all maps. The other points displayed are the Independent and Dependant map axis parameters, "Desired Engine Speed", "Desired Combustion Time", "Actual Air Pressure", "Desired Air Pressure" and the "Map Compatibility Code".

The "Map Compatibility Code" is saved in the map file during the "Save to File" process. This is the code which identifies the "Map Adjustment" feature version, Engine Model and Rating Interlock that is compatible with this file. If this code in the file does not match the code displayed in the "Gas Mass Fuel Flow" map "Monitored ECM Parameter" screen, the maps are not compatible and will not be loaded into Cat ET if it is attempted.

For example, a map file that is saved from a G3616 engine is not compatible with a G3606 engine. A file that is saved from a G3606 that has a rating interlock of 1 is not compatible with a G3606 that has a rating interlock of 2.

Illustration 20	g01327633
Map View

Map View - When "Map View" box is checked, Cat ET displays a two dimensional view of the selected map axis points and will show a variance of the values with the current map values operating in the ECM. Use a mouse right click on the map to display the map in full screen. The "ESC" key will return the map to normal display size.

Illustration 21	g01327635
3D Map View

3D Map View - When the "3D Map View" box is checked, this displays a three dimensional view of the selected map. Use a mouse right click on the map to display other map view features. The map can be viewed in full screen and the view can be rotated. The "ESC" key will return the map to normal display size. The "3D Map View" is not available for" Map 3: Gas Mass Fuel Flow".

Map Screen Layout

Independent Parameter Axis - The first one or two columns define the map points that will be adjusted. If it is a "3D Map", column one and two contain the axis points for the independent parameters such as "Engine Speed RPM" or "Mass Fuel Flow Per Stroke lb/strk". If a "2D Map" is displayed, then only column one is the independent parameter. These are used to define the location on the map where the changes will take affect.

Dependant Axis - The Dependant Axis, which contains the map values to be adjusted, is either located in the second or third column. This is the column with the up and down arrows at the right side of each point in the column. Select the up arrow to increase or select the down arrow to decrement the value of the point. If the "Data Modify Mode" is "All Values", increasing or decreasing one parameter will change all values which are being displayed in the selected map.

"Modifiable Range" - This is the allowable range, usually +/- 0.1 unit, that the point can change for each submission.

"Valid Range" - This is the total allowable range that the point can be changed for each map point.

"Offset" - This displays the difference between the "Current" map operating in the ECM and the value in the dependant axis column.

"Resolution" - This column displays the resolution of the parameter.

Map Adjustment Buttons

Factory - This button is used to reset the map that is currently selected or to reset all of the maps to default values that were programmed at the factory. Refer to the ""Factory Button" " section for more information.

Submit - This button is used from the "Working map" only. This button will start the process to submit the map changes to the ECM. Refer to the ""Map Submission Process" ".

Illustration 22	g01327604
Copy to Working

Copy to Working - This button transfers the selected map type: "Base", "Previous", "Current", or "File" to the "Working" map. This informational dialog is displayed. Select "Yes" to continue or "No" to stop the process.

Load from File - This button loads a "File Map" into the "Map Adjustment" feature. Refer to the ""Load from File" ".

Save to File - This button saves map adjustment changes to a file on the PC. Refer to the ""Save to File" ".

More... - This button provides access to the "Setup Configuration" and "Calibration Feedback" features. Refer to the ""More Button" " section for more information.

Factory Button

Illustration 23	g01327602
Factory button

The "Factory" button is used to restore the ECM operation to the standard factory maps which are internal to the file. Select "All Maps" to reset all four maps. Or select the "Selected Map" option to change just the current selected map.

Illustration 24	g01313458
Window prior to setting all the maps back to the default to the values

Illustration 24 is an example of the confirmation dialog prior to setting all the maps back to the default to the values that are programmed at the factory. Select "Yes" to continue or select "No" to abort.

Note: In ET2006BV1.0, the "Factory" button only resets the "Selected Map" only and does not provide an option to reset "All Maps". Each map will have to be selected and reset individually.

Load from File

Illustration 25	g01327683
Load from file

Load from File - Select this button to load a map from a "Map Adjustment" map file into Cat ET for viewing. Browse to the directory where the file was stored using the "Save to File" feature. Select the file and then select the "Open" button to load the data into Cat ET.

Illustration 26	g01327687
Window once a "Map Adjustment" map file has been loaded

When the file has been loaded, an informational message will be displayed and the Map Type will be "File". Select "OK" to acknowledge the dialog window.

Note: The file will not be loaded if the "Map Compatibility Code" does not match the code in the ECM. An error dialog box will be displayed if this occurs.

Illustration 27	g01327688
File map

Review the "File" map to determine that this does contain the correct values. Select the "Copy to Working" map to transfer the values from the "File" map to the "Working map".

Illustration 28	g01327691
Confirmation box

A confirmation box will be displayed, select "Yes" to proceed with the changes.

Illustration 29	g01327693
Map Type "Working map"

Select the Map Type "Working map". Complete the transfer of the "File" map by selecting the "Submit" button and complete the submission.

Note: A "File" map may contain adjustments that are larger then the "Modifiable Range", but within the "Valid Range". The ECM will accept these changes with one submission process.

Save to File

Illustration 30	g01327667
Save to File

Save to File - This button stores the values of the four maps which are currently operating in the ECM to a file on the PC. Also stored in this file is the "Map Compatibility Code" which is specific to each engine model and rating. The file name will default to the engine serial number, date, and map compatibility code, but this can be modified as needed. Select the "Save" button to store the date in the selected path and file.

Illustration 31	g01327675

After the "Save" button is selected, the map adjustment data is stored to the selected file. This map file can later be used to update other engines with the same maps, using the "Load from File" button provided that the engine is of the same model and rating.

More Button

Illustration 32	g01313289
More button

The "More..." button is used to select for the "Setup Configuration" or to select for "Calibration Feedback Enable/Disable".

Note: The "More..." button is not available in ET2006BV1.0. This version of Cat ET only supports the "Calibration Feedback Enable/Disable" function.

Calibration Feedback Enable/Disable

The "Calibration Feedback Enable" or the "Calibration Feedback Disable" is used to turn the "Calibration Feedback" on or off. The "Map Adjustment" feature must be set to "Calibration Feedback Enable" (open loop) mode when you are modifying the "Desired Air to Fuel Ratio" or the "Desired Combustion Time" maps.

Illustration 33	g01327657
Calibration feedback enable

Calibration Feedback Enable - When the "Calibration Feedback" is enabled the "Gas Fuel Correction Factor" (FCF) will remain constant at 100 percent. When the engine is operating in "Exhaust Temperature Feedback" or in "Combustion Feedback", the FCF can vary within the valid range of 80 percent to 120 percent. If the control system is operating in "Calibration Feedback" mode and the communication between Cat ET and the engine control is interrupted, the engine control will return to normal feedback operation. If this occurs, the "Gas Fuel Correction Factor" will start adjusting within the valid range. If this occurs, select the "Calibration Feedback Disable" and then "Calibration Feedback Enable" to restart the "Calibration Feedback" mode.

Illustration 34	g01327662
Calibration feedback disable

Calibration Feedback Disable - To determine the impact of the map adjustments on engine performance, select the "Calibration Feedback Disable" button to return the engine to normal feedback operation. The control will determine which feedback mode to use, based on the current operating conditions.

Note: If "Calibration Feedback Enable" is shown when the "More..." button is clicked, the engine is operating currently in the appropriate "Emissions Feedback" mode. If "Calibration Feedback Disable" is shown when the "More..." button is clicked, the engine is currently in the "Calibration Feedback" mode.

Setup Configuration

The Setup Configuration is used to change the "Fuel Quality Configuration" or the "Gas Specific Gravity".

Illustration 35	g01313292
"Setup configuration window"

When the "Setup Configuration" is selected, a window will appear in order to select between "Fuel Quality Configuration" or "Gas Specific Gravity". Refer to illustration 35.

Illustration 36	g01313344
"Fuel Quality Configuration" window

Illustration 36 is an example of the window in order to change the "Fuel Quality Configuration".

Illustration 37	g01313369
"Gas Specific " window

Illustration 37 is an example of the window in order to change the "Gas Specific Gravity".

Map Submission Process

Illustration 38	g01327639
Factory passwords window

Once the initial map adjustment changes are made and the "Submit" button is pressed, factory passwords are required to submit the changes. Entering the factory passwords is only required the first time changes are submitted for the session. If the "Map Adjustment" feature is closed and opened again, factory passwords are required again for the new session.

Refer to Special Instruction, REHS1238, "Obtaining Factory Passwords and Software Enabled Attachments"

Illustration 39	g01327641
Passwords are accepted notification

If the passwords are accepted, the Security Level Information box is displayed, select "OK" to continue.

Illustration 40	g01327642
Confirmation box

A confirmation box is then displayed before each submission is sent to the ECM. Select "Yes" to continue or "No" to abort.

Illustration 41	g01327643
Sending maps to the ECM

The maps will then be transferred to the ECM and a status screen is displayed to show the progress. When this step is completed, the new map changes are functioning in the ECM.

Illustration 42	g01327647
Loading maps from the ECM

After the ECM has accepted the maps, Cat ET loads the map values from the ECM and compares them to the maps which were transferred.

Illustration 43	g01327650
The ECM accepted the submitted map

Cat ET then compares the new ECM maps with the maps which were transferred and displays the appropriate information box.

At this point, confirm the engine performance changes and determine if additional adjustments are required. If additional adjustments are required. Return to the "Working map" and adjust as necessary.

Once the engine is operating as it is desired, use the "Save to File" button in order to save the changes to a file on the PC. This should be archived in a file location on the PC if the file is needed in the future for an ECM replacement or to configure another engine of the same model and the same power rating.

Adjusting the Maps Using the Map Adjustment Feature

Engine Maintenance and Pre-checks

The following engine maintenance must be performed prior to using the "Map Adjustment" software:

• Calibrate the Air/Fuel Pressure Module to match site barometric air pressure

• Set the "Fuel Quality Configuration" and "Gas Specific Gravity" to the values of the fuel analysis

• Engine Valve Lash - Inspect/Adjust

• Gas Admission Valve Lash - Inspect/Adjust

• Ignition System Spark Plugs - Clean/Gap or Replace

• Actuator Linkage - Inspect/Adjust

Refer to the ""Engine Maintenance Prior to Using the Map Adjustment Feature" " section.

Engine Tune

1. Operate engine at rated speed and at full load until normal operating temperatures for the jacket water, for the SCAC, and for the engine oil are reached.

2. Operate engine at the most commonly used load point and steady state conditions if the conditions are different then they are in Step 1.

3. Use the Cat ET "Prechamber Calibration" feature and adjust the needle valves so that the cylinder combustion burn times are within +/- 0.2 ms of the "Desired Combustion Time" displayed on the "Monitored ECM Parameter".

4. Record the needle valve settings and verify that the average settings are approximately three to four turns open after final tune. If not, retune the needle valves to the combustion burn time that results in the above average needle valve settings.

   Note: The combustion burn time is used to tune the needle valves is irrelevant at this point since the goal is to establish a proper tune for the needle valves before starting the actual engine mapping process.

Refer to the ""Engine Maintenance Prior to Using the Map Adjustment Feature" " section.

Mapping Procedure to Achieve Desired NOx Emissions

1. Verify the control system is operating in "Calibration Feedback" mode.

2. Using a calibrated exhaust emissions analyzer, measure and record NOx emissions at the intended operating speed and load conditions.

3. Determine how much the NOx emissions deviate from the target which is 70 ppm for the 0.7 g/bhp-hr standard ratings or 55 ppm for the 0.5 g/bhp-hr low emission (LE) ratings.

4. Use the guideline that 0.1 air to fuel ratio and 0.1 ms combustion burn time will change the NOx emissions approximately ten ppm. Note, increasing the air to fuel ratio provides a leaner air to fuel mixture and reduces NOx. Conversely, decreasing the air to fuel ratio provides a richer air to fuel mixture and increases NOx.

5. Using the "Map Adjustment" feature, open the "Desired Air to Fuel Ratio" map and globally adjust the "Desired Air to Fuel Ratio" map from 0.00180 to 0.00420 mass fuel flow per stroke (lb/strk) over the 750 to 1100 RPM operating range using the guideline in Step 4.

6. Measure NOx again to see if the desired emissions level has been achieved.

7. If further "Desired Air to Fuel Ratio" map adjustments are needed in order to achieve the desired NOx, repeat Steps 5 and 6 until the desired NOx level is obtained and then save the final map changes.

8. Once the desired NOx level has been achieved, record the engine average combustion burn time that is displayed in the "Monitored ECM Parameter".

9. Open the "Desired Combustion Time" map and globally adjust the "Desired Combustion Time" from 0.00180 to 0.00420 mass fuel flow per stroke (lb/strk) over the 750 to 1100 RPM operating range by the difference between the combustion time displayed at the point the engine is currently operating and the combustion time recorded in Step 8. Increasing the "Desired Combustion Time" provides a leaner air to fuel mixture and reduces NOx. Conversely, decreasing "Desired Combustion Time" provides a richer air to fuel mixture and increases NOx.

10. Put the control system in "Combustion Feedback" mode and measure NOx emissions. NOx must be the same as recorded when operating in "Calibration Feedback" mode.

11. If further "Desired Combustion Time" map adjustments are needed in order to achieve the desired NOx emissions, repeat Steps 9 and 10 until the desired NOx level is obtained. Make sure the control system is in "Calibration Feedback" mode when making adjustments to the "Desired Combustion Time" map and then return to "Combustion Feedback" mode when measuring NOx so the control system is operating off the "Desired Combustion Time" map and not the "Desired Air to Fuel Ratio" map. Save the final map changes.

12. If the engine will be operating at other speed and load conditions besides the above point, the "Desired Air to Fuel Ratio" map and the "Desired Combustion Time" map can be adjusted to achieve the desired NOx emissions for those specific operating points too. Operate the engine at the alternate speed and load conditions and adjust the relevant "Desired Air to Fuel Ratio" map and the relevant "Desired Combustion Time" map points following the above procedure.

Gas Mass Fuel Flow Map Adjustment

1. Operate the engine at the maximum site rating and check the engine load factor in the "Monitored ECM Parameter". If the engine load factor is above 100 percent, use the "Map Adjustment" feature to derate the engine so the load factor matches the site rating.

2. To adjust the "Gas Mass Fuel Flow" map values, operate the engine at the maximum site rating, then reduce the fuel flow so the engine load factor is 100 percent.

3. Adjust the remaining "Gas Mass Fuel Flow" points between 675 and 1050 RPM so the map is linear.

4. Above 1050 RPM, the fuel flow map needs to drop quickly in order to protect the engine from an overspeed condition. Adjust the 1125 RPM fuel flow point to maintain the same approximate fuel reduction as the factory map contained and save the final map changes.

Transient Air Fuel Ratio Limit Map Adjustment

1. Adjusting the "Transient Air Fuel Ratio Limit" map will only be required in rare instances where adjusting the "Engine Start Fuel Burst Command" through its range of adjustment does not improve a hard starting condition. Use the Cat ET Data Logger function to record the following channels: "Engine Speed", "Desired Engine Speed", "Actual Air Pressure", "Desired Air Pressure", "Air to Fuel Differential Pressure", "Actual Air to Fuel Ratio", "Desired Air to Fuel Ratio", "Engine Load Factor", "Percent Fuel Position", "Percent Choke Command" and "Wastegate Position Command".

2. Analyze the logged data and determine if the actual air to fuel ratio is significantly less than the "Desired Air to Fuel Ratio". If the "Desired Air to Fuel Ratio" is greater than the actual air to fuel ratio (greater by five air to fuel ratios or more), the engine is probably too rich during the starting sequence.

3. To improve starting, use the "Map Adjustment" feature to increase the "Transient Air Fuel Ratio Limit" map points between 0.0 to 0.06801 and 0 to 600 RPM. The amount of change will require some trial and error adjustments. A good procedure to begin with is to increase the "Fuel Quality Configuration" value in the setup configuration screen in 25 BTU steps to provide a leaner air to fuel mixture while conducting starting tests with each "Fuel Quality Configuration" (BTU) value. From these tests, determine the "Fuel Quality Configuration" value that produces the best starting characteristics.

4. Determine the percentage change between the fuel analysis value and the optimum "Fuel Quality Configuration" value determined in Step 3.

5. Raise the "Transient Air Fuel Ratio Limit" map points across the mass fuel flow and speed ranges in Step 3 by the percentage change between the fuel analysis value and the optimum "Fuel Quality Configuration" value that is determined in Step 4.

6. Raise the "Desired Air to Fuel Ratio" map by the same percentage as the "Transient Air Fuel Ratio Limit" map, across the 0.0 to 0.00420 mass fuel flow and 350 to 600 RPM ranges.

7. Use the "3D Map View" screen to visually see the changes made in Step 5. Determine how much the 675 RPM points need to be adjusted in order to smooth the transition between 600 and 750 RPM. Save the final map changes.

8. Switch to the "Desired Air to Fuel Ratio" map and "3D Map View" screen to visually see the changes made in Step 6. Determine how much the 650 RPM points need to be adjusted in order to smooth the transition between 600 and 700 RPM. Save the final map changes.