C13 and C15 On-highway Engines Caterpillar

"Vehicle Speed Calibration"

The Engine Control Module (ECM) uses the value of this parameter in order to translate the vehicle speed signal into kilometers per hour (miles per hour). This parameter is programmed in pulses per kilometer (PPKM) or pulses per mile (PPM). This parameter must be programmed. This parameter affects the cruise control and the ECM speedometer signal. Also, this parameter can affect the PTO operation, extended idle and trip totals.

"Vehicle Speed Cal (J1939 - Trans)"

The "Vehicle Speed Cal (J1939 - Trans)" is used when the ECM is configured to use the speed of the transmission output shaft in order to calculate vehicle speed. The "Vehicle Speed Input" parameter must be programmed to "Vehicle Speed Cal J1939 - Trans". This value represents the revolution of the transmission output shaft as revolutions per kilometer (revolutions per mile). This parameter must be programmed. This parameter affects the cruise control and the ECM speedometer signal. Also, this parameter can affect the PTO operation, extended idle and trip totals.

"Vehicle Speed Cal (J1939 - ABS)"

The "Vehicle Speed Cal (J1939 - ABS)" is used to calculate vehicle speed by using the input from the wheel speed. The data from the wheel speed is transmitted via the J1939 data link. The "Vehicle Speed Input" parameter must be programmed to "Vehicle Speed Cal J1939 - ABS". The manufacturer of the ABS must transmit tire revolutions per mile that is based on the tire size. If the tire size is changed from the tire size that is programmed in the ABS the "Vehicle Speed Cal (J1939 - ABS)" must be changed.

The value of this parameter is a ratio. If the actual tire size is equal to the tire size that is programmed in the ABS, the "Vehicle Speed Cal (J1939 - ABS)" parameter will be "1". Determine the ratio by dividing the tire revolutions per mile that is transmitted by the ABS by the actual tire revolutions per mile. Contact the manufacturer of the ABS in order to verify that this message is supported.

If the "Vehicle Speed Input" parameter is programmed to "Vehicle Speed Cal J1939 - ABS", this parameter must be programmed. If this parameter is not programmed, a 630-2 code is activated. This parameter affects the cruise control and the ECM speedometer signal. Also, this parameter can affect the PTO operation, extended idle and trip totals.

"Vehicle Speed Limit"

The "Vehicle Speed Limit" is the maximum vehicle speed that is allowed by the ECM. The ECM disables fuel flow above this speed. An inexperienced driver may think that something is wrong with the engine because the ECM does not fuel the engine above this vehicle speed limit. Vehicle speed limiting allows the implementation of a gear fast/run slow specification for the truck. The gear fast/run slow specification for the truck improves fuel economy while the parameter for the vehicle speed limit limits the maximum vehicle speed of the truck.

Note: The driver reward can be used to automatically adjust the VSL according to the driver's operating techniques.

"VSL Protection"

The "VSL Protection" is the maximum engine rpm when there is a problem with the vehicle speed signal that is detected by the ECM. The ECM limits the engine speed to the value of this parameter when the ECM senses no vehicle speed signal, and there is a load on the engine. This feature prevents tampering by limiting engine speed if the ECM does not detect a valid vehicle speed signal.

Note: "VSL Protection" is disabled when this parameter is programmed to the programmed TEL rpm and the vehicle speed sensor is disconnected.

"Tachometer Calibration"

The ECM uses the value of this parameter in order to translate the engine speed signal into revolutions per minute for a tachometer. The "Tachometer Calibration" is programmed in pulses per revolution (PPR). The programmable range is from 2.0 PPR to 500.0 PPR in 0.1 PPR increments.

"Soft Vehicle Speed Limit"

This parameter operates in conjunction with the "Vehicle Speed Limit" parameter. The "Soft Vehicle Speed Limit" limits the vehicle speed within the following range:

• The minimum value is 4 km/h (2.5 mph) below the programmed "Vehicle Speed Limit" at full load.

• The maximum value is 4 km/h (2.5 mph) above the selected "Vehicle Speed Limit" at no load.

"Two Speed Axle - Low Speed Range Axle Ratio"

The "Two Speed Axle - Low Speed Range Axle Ratio" must be programmed when a "Two-Speed Axle On/Off Switch" is used by the ECM to adjust the "Vehicle Speed Calibration". When a two-speed axle is used, the change in gear ratios from the high speed range to the low speed range alters the vehicle speed signal. Since the vehicle speed signal has been altered, a calibration adjustment is required to ensure that the ECM driven speedometer and the information that is stored in the ECM correctly reflect the actual vehicle speed. This parameter must be programmed to the actual value of the axle ratio for the low speed range. This parameter only requires programming when the "Two-Speed Axle Switch" parameter is enabled.

"Nominal Axle Ratio - High Speed Range Axle Ratio"

The "Nominal Axle Ration - High Speed Range Axle Ratio" must be programmed when a "Two-Speed Axle On/Off Switch" is used by the ECM to adjust the "Vehicle Speed Calibration". When a two-speed axle is used, the change in gear ratios from the high speed range to the low speed range alters the vehicle speed signal. Since the vehicle speed signal has been altered, a calibration adjustment is required to ensure that the ECM driven speedometer and the information that is stored in the ECM correctly reflect the actual vehicle speed. This parameter must be programmed to the actual value of axle ratio for the high speed range. This parameter only requires programming when the "Two-Speed Axle Switch" parameter is enabled.