176 RENR5042-02 Troubleshooting Section If the diagnostic code recurs, replace the ECM. Refer to Troubleshooting, “Replacing the ECM”. Verify that the problem is resolved. Note: The lamp will only turn off only if a “Warning”, a “Derate”, or a “Shutdown” condition does not exist. STOP. Expected Result: The warning lamp turns on and the warning lamp turns off per the above description. i02290063 Warning Lamp Circuit - Test Results: OK – The warning lamp appears to be operating correctly at this time. STOP. SMCS Code: 7431-038 System Operation Description: Not OK The warning lamp is not functioning correctly. Proceed to Test Step 2.
The warning lamp is a maintenance indicator that is based on the PM levels that are programmed into the Electronic Control Module (ECM). The warning lamp will turn on when a warning, a derate, or a shutdown condition exists. Test Step 2. Inspect the Electrical Connectors and the Wiring A. Turn the keyswitch to the OFF position. Use this procedure to troubleshoot any suspect problems with the circuit for the warning lamp. g01122447 Illustration 97 Schematic for the warning lamp The ECM provides a path to ground for the warning lamp. When the ECM connects the warning lamp to ground the warning lamp will turn on. Test Step 1. Check for Normal Operation of the Warning Lamp A.
Monitor the warning lamp. g01119456 Illustration 98 a. Turn the keyswitch to the ON position. The warning lamp should turn on for five seconds. Then, the lamp should turn off. Left side view (1) P61 customer connector (2) J1/P1 ECM connectors