PLANETARY 8T9345 - Caterpillar

MID 027 CID 0041 FMI 04Conditions Which Generate This Code:This diagnostic code is recorded when the ECM reads the voltage of the 8 volt DC supply circuit (wire R800-OR(Orange)) and the voltage is below normal.Note: Use a digital multimeter for the measurements in this procedure.System Response:Components that receive power from the 8 volt DC supply will not be available. Check for other logged diagnostic codes.Test Step 1. CHECK THE VOLTAGE AT THE ECM.
Turn the disconnect switch and the key start switch to the ON position.
Check the voltage at the connector of the ECM from contact J1-44 (8 volt DC supply) to contact J1-13 (ground). Use the multimeter probes to measure the voltage. Do NOT disconnect the machine harness from the ECM. Expected Result:The voltage is 8.0 0.5 DCV.Results:
OK - The voltage is 8.0 0.5 DCV. The 8 volt DC supply voltage is correct. Verify that the diagnostic code is present. If the diagnostic code is still present the ECM has failed. Proceed to test step 2.
NOT OK - Voltage is NOT 8.0 0.5 DCV. The voltage is less than 8.0 0.5 DCV. The ECM has failed.Repair: Check the circuit again. If the Caterpillar Electronic Technician (Cat ET) is available, use the Cat ET service tool in order to perform a “Wiggle Test” on the machine wiring harness. The “Wiggle Test” can detect shorts and opens in the machine wiring harness that are momentary or intermittent.It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". STOPTest Step 2. CHECK FOR A SHORT TO GROUND.
Disconnect any sensor that uses the 8 volt DC supply voltage from the machine harness.
At the harness connector for the ECM, measure the resistance between frame ground and contact J1-44 of the 8 volt DC supply circuit. Expected Result:The resistance is greater than 5000 ohms.Results:
OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The ECM has failed.Repair: Check the circuit again. If the Cat ET is available, use the Cat ET service tool in order to perform a “Wiggle Test” on the machine wiring harness. The “Wiggle Test” can detect shorts and opens in the machine wiring harness that are momentary or intermittent.It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". STOP
NOT OK - The resistance is less than 5000 ohms. If the resistance is less than 5000 ohms with all of the sensors disconnected from the machine harness, the machine harness is shorted to ground. Proceed to Test Step 3.Test Step 3. DISCONNECT THE SENSOR(S).
Turn the key start switch and the disconnect switch to the ON position.
After disconnecting the sensor(s), check the Cat ET for