CLAMP 0031049 - Caterpillar

Illustration 1 g02150590
Connections of the 10 VDC power supply
This diagnostic code is associated with the 10 VDC power supply. The FMI 03 is recorded when the ECM reads the voltage of the supply circuit as higher than the normal voltage.The possible causes of this diagnostic code are listed:
The voltage supply is shorted to the +battery circuit in the harness.
A component that uses the supply has failed.
The ECM has failed. An ECM failure is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 1482 - FMI 03 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. Check for the correct voltage at the ECM
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
Insert multimeter probes into the back of the ECM at contact J1-69 and contact J1-56. Measure the voltage that is supplied by the ECM. Expected Result:The voltage is 10 0.5 VDC.Results:
YES - The voltage is 10 0.5 VDC. The sensor supply voltage is correct. The ECM is correct. Proceed to Test Step 2.
NO - The voltage is greater than 10 0.5 VDC. The voltage that is supplied by the ECM is not correct.Repair: Prior to replacing an ECM, always contact your technical communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, replace the ECM. Refer to Troubleshooting, "Electronic Control Module (ECM) - Replace".STOPTest Step 2. Check the harness for a short to the +battery circuitThe disconnect switch and the key start switch remain in the ON position. The J1 machine harness connector remains disconnected from the ECM.
Disconnect the J2 machine harness connector from the ECM.
At the machine harness connector for the ECM, measure the resistance from connector contact J1-69 wire (709-OR(Orange)) to all of the other contacts that are used in the ECM connectors. Refer to Troubleshooting, "Wiring Harness (Short Circuit) - Test". Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
YES - Each resistance measurement is greater than 5000 ohms. The circuit is correct. The ECM may be faulty. Proceed to Test Step 3.
NO - One or more of the resistance measurements are less than 5000 ohms.Repair: The machine harness is shorted to the +battery circuit. Repair the machine harness or replace the machine harness.STOPTest Step 3. Check the status of the diagnostic code
Inspect the harness connectors. Clean the contacts of the harness connectors and check the wires for damage to the insulation. Damage is caused by excessive heat, battery acid, or chafing.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
Reconnect all harness connectors in order to