Use this procedure to troubleshoot any suspect problems with the following indicator lamps:
- Maintenance indicator lamp
- Diagnostic lamp
- Warning lamp
The indicator lamps are activated by the Electronic Control Module (ECM) in order to inform the operator of various engine events.
The most likely cause of a problem with an indicator lamp is the bulb. The next most likely cause is a problem with a wire or with a connector. The least cause is a problem with the ECM.
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| Illustration 1 | g01167879 |
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Schematic for the indicator lamps | |
Test Step 1. Inspect the Electrical Connectors and the Wiring
- Turn the keyswitch to the OFF position.
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Illustration 2 g01167488 Engine view (typical example)
(1) J1/P1 ECM connectorShow/hide table
Illustration 3 g01146383 Engine view (typical example)
(2) J61/P61 customer connectors - Thoroughly inspect connectors (1) and (2). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
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Illustration 4 g01167876 P1 terminals for the indicator lamps
(P1-28) Diagnostic lamp
(P1-29) Warning lamp
(P1-30) Maintenance indicator lampShow/hide table
Illustration 5 g01167878 J61/P61 terminals that are associated with the indicator lamps
(13) Maintenance indicator lamp
(24) Diagnostic lamp
(25) Warning lamp - Perform a
45 N (10 lb) pull test on each of the wires that are associated with the indicator lamps. - Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
- Check the harness and wiring for abrasions and for pinch points from the indicator lamps to the ECM.
Expected Result:
All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.
Results:
- OK - The connectors and wiring appear to be OK. Proceed to Test Step 2.
- Not OK - There is a problem in the connectors and/or wiring.
Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.
STOP
Test Step 2. Check for Normal Operation of the Lamp
- Turn the keyswitch to the ON position and monitor the indicator lamps.
Expected Result:
The indicator lamps turn on for five seconds. Then, the indicator lamps turn off.
Results:
- OK - The indicator lamps turn on for five seconds. Then, the indicator lamps turn off.
Repair: The problem appears to be resolved. The original problem was probably caused by a poor electrical connection. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".
STOP
- Not OK - An indicator lamp does not turn on. Proceed to Test Step 3.
Test Step 3. Measure the Voltage at the Lamp Socket
- Use a test lamp to check for voltage at the suspect lamp socket within the first five seconds after the keyswitch is turned on.
Expected Result:
The test lamp illuminates during the first five seconds after the keyswitch is turned on.
Results:
- OK - The test lamp illuminates during the first five seconds after the keyswitch is turned on.
Repair: Replace the bulb.Verify that the repair eliminates the problem.
STOP
- Not OK - The test lamp did not illuminate during the first five seconds after the keyswitch was turned to the ON position. Proceed to Test Step 4.
Test Step 4. Bypass the ECM in order to Test the Lamp Circuit
- Fabricate a jumper wire that can be used to connect two terminals at the P1 ECM connector. Crimp connector pins to both ends of the wire.
- Disconnect the J1/P1 connectors.
- Use the jumper wire to short one leg of the indicator lamp to the appropriate circuit connection. Refer to Table 1 for the appropriate terminals.
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Table 1 P1 Terminals for the Connection of the Jumper Wire Indicator Lamp Terminals Maintenance indicator P1-30 P1-63 Diagnostic lamp P1-28 P1-63 Warning lamp P1-29 P1-63 - Turn the keyswitch to the ON position and observe the indicator lamp.
- Remove the jumper wire and observe the indicator lamp.
Expected Result:
The indicator lamp turns on while the jumper wire is connected to both terminals. The indicator lamp turns off when the jumper wire is removed.
Results:
- OK - The indicator lamp turns on while the jumper wire is connected to both terminals. The indicator lamp turns off when the jumper wire is removed. The circuit for the indicator lamp is functioning properly.
Repair: Perform the following procedure:
- Connect the J1/P1 connectors.
- Turn the keyswitch to the ON position and monitor the indicator lamps.
The indicator lamps should turn on for five seconds. Then, the indicator lamps should turn off.
If the indicator lamps turn on for five seconds, the problem is resolved. Return the engine to service.
STOP.
- If the indicator lamps do not turn on for five seconds, there may be a problem with the ECM. It is unlikely that the ECM has failed. Exit this procedure and perform this entire procedure again.
If the problem is not resolved, replace the ECM. Refer to Troubleshooting, "Replacing the ECM".
STOP
- Not OK - The indicator lamp does not turn on while the jumper wire is connected to both terminals. There is a problem in the wiring for the indicator lamp. There may be a problem in a connector.
Repair: Repair the lamp circuit. Verify that the repair eliminates the problem.
STOP