320D3 and 323D3 Excavators Machine Electronic Control System Caterpillar

Switch Circuits - Test

Usage:

Machine ECM

The following is a list of codes that are associated with the window washer switch of the machine.

Show/hide table

Table 1
Machine ECM (MID 299)
DTC	Code Description	System Response
2913-3	Window Washer Switch : Voltage Above Normal	Switch will not function.
2913-6	Window Washer Switch : Current Above Normal	Switch will not function.

The Window Washer Switch has one input to the switch panel. The input is normally open. When a circuit is measured with a voltmeter, an open circuit will measure approximately 8 VDC to ground. A closed circuit will measure approximately 0 VDC to ground.

The diagnostic code is recorded when the status of both the inputs are open.

Possible Causes for an FMI 3 Diagnostic code are:

The ground wire is open.
The signal is permanently open.
The signal is permanently closed.
The switch has failed.
The ECM has failed. A failure of the Machine ECM is unlikely.

Possible Causes for an FMI 6 Diagnostic code are:

A short to ground.
The switch has failed.
The ECM has failed. A failure of the Machine ECM is unlikely.

Show/hide table




Illustration 1	g06326356
Window Wiper Switch schematic

Note: The diagram above is a simplified schematic of the Switch Panel connections. The schematic is electrically correct. However, not all the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, M0094859 for 320D3 and M0094901 for 323D3 excavator electrical systems.

Note: The following test procedure may create other diagnostic trouble codes. Ignore these created diagnostic trouble codes and clear the diagnostic trouble codes when the original diagnostic trouble code has been corrected.

Note: The switch in this circuit is enclosed in a module. The switch for this circuit is not independently serviceable. The module must be replaced if the switch fails.

Diagnostic Trouble Code Procedure

Note: Prior to beginning this procedure, inspect the harness connectors that are involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. Check the wiring for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing a troubleshooting procedure.

Identify the active FMI code associated with the faulty component.
Determine which code is present and use the list below to determine the correct procedure to follow.
- FMI 3 diagnostic code, proceed to Table 2.
- FMI 6 diagnostic code, proceed to Table 3.

Show/hide table

Table 2
Begin Process For FMI 3 Troubleshooting HERE
Troubleshooting Test Steps	Values	Results
1. Check The Ground Circuit For An Open A. Turn the disconnect switch and the key start switch to the OFF position. B. Disconnect the switch from the machine harness. C. Measure the resistance between frame ground and the "washer" contact on the switch panel.	The reading is less than 5 Ω.	OK - The resistance is less than 5 Ω. Repair: Replace the module for the wiper control. Proceed to Test Step 2. NOT OK - The resistance is greater than 5K Ω. Repair: The "washer" circuit wire is open in the machine harness. Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
2. Check The Signal Circuits In The Harness For An Open A. Reconnect the "wiper control" module to the machine harness. B. Disconnect the C301, C302, and C303 harness connectors from the switch panel. C. At the machine harness connector for the switch panel, check for continuity between "washer" contact and all sources of negative battery. D. Press the washer switch and release the switch. (Checking the switch for continuity.)	The continuity check is correct.	OK - The continuity check is correct. Proceed to Test Step 3. NOT OK - The continuity check is not correct. Repair: There is an open in the signal circuit of the machine harness. Repair or replace the machine harness. STOP
3. Check If The Diagnostic Code Remains A. Inspect the harness connectors and clean the contacts of the harness connectors. B. Reconnect all harness connectors. C. Turn key start switch and disconnect switch to the ON position. D. Operate the machine. E. Check the status of the diagnostic code.	The diagnostic code is not active.	OK - The diagnostic code is no longer active. The problem may be intermittent. Resume normal machine operation. STOP NOT OK - The diagnostic code is active. The ECM may have failed. Repair: A failure of the ECM is unlikely. If the cause of the diagnostic code is not found, replace the ECM. Prior to replacing an ECM, always contact your dealer for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM must be replaced, refer to Troubleshooting, "ECM - Replace". STOP

Show/hide table

Table 3
Begin Process For FMI 6 Troubleshooting HERE
Troubleshooting Test Steps	Values	Results
1. Check the Ground Circuit Of The Switch In The Harness A. Turn key start switch and disconnect switch to the OFF position. B. Disconnect the machine harness connectors from the switch panel. C. Measure the resistance between the "washer" connection on the switch panel and the ground contact.	The resistance is less than 5 Ω.	OK - The circuit is correct. Proceed to Test Step 2. NOT OK - The resistance is greater than 5K Ω. The circuit is open. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose connection or a corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
2. Check The Switch Circuits For A Short To The Ground Circuit A. The machine harness connectors remain disconnected from the switch panel. B. Turn the disconnect switch and the key start switch to the OFF position. C. Disconnect the machine harness connector from the "wiper control" module. D. At the harness connector for the switch panel, measure the resistance between the "washer" contact and all contacts used in the machine harness for the switch panel.	Each reading is greater than 5K Ω.	OK - The wiring harness is correct. Repair: Replace the "wiper control" module. Proceed to Test Step 3. NOT OK - One or more of the measurements were less than 5 Ω. A short exists in the wiring harness. Repair: Repair or replace the machine harness. Note: A resistance greater than 5 Ω but less than 5K Ω indicates a loose or corroded connection in the circuit. A resistance measurement greater than 5K Ω indicates an open in the circuit. STOP
3. Check If The Diagnostic Code Remains A. Inspect the harness connectors and clean the contacts of the harness connectors. B. Reconnect all harness connectors. C. Turn key start switch and disconnect switch to the ON position. D. Operate the machine. E. Check the status of the diagnostic code.	The diagnostic code is not active.	OK - The diagnostic code is no longer active. The problem may be intermittent. Resume normal machine operation. STOP NOT OK - The diagnostic code is active. The ECM may have failed. Repair: A failure of the ECM is unlikely. If the cause of the diagnostic code is not found, replace the ECM. Prior to replacing an ECM, always contact your dealer for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECM must be replaced, refer to Troubleshooting, "ECM - Replace". STOP