TBG. ARRANGEMENT (6NG) 2U9807 - Caterpillar

Illustration 1 g03746294
Schematic for the Sensor Power Supply (10 VDC)
This diagnostic code is recorded when the voltage of the sensor supply circuit (799-WH(White)) is above the normal range. Any sensor that is connected to this supply may not operate properly or the sensor may be damaged. If there is not a sensor connected, then this fault can be considered a nuisance fault. The possible causes of this diagnostic code are listed below:
The circuit for +V (799-WH(White)) to the sensor is shorted to the battery.
The ECM is faulty. ECM failure is unlikely.Test Step 1. CHECK FOR THE CORRECT 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 Brake ECM, from contact J1-69 to contact J2-63 (ground). Use 7X-1710 Cable Probes (or similar) to measure the voltage. Do NOT disconnect the machine harness from the Brake ECM. Expected Result:The voltage is 10.0 0.5 DCV.Results:
OK - Voltage is 10.0 0.5 DCV. The sensor supply voltage is correct. Verify that the diagnostic code is present. If the diagnostic code is still present, the ECM has likely failed.Repair: Failure of the ECM is unlikely. Perform this procedure again. Also, recheck if the diagnostic code is active. If the cause of the diagnostic code is not found, replace the ECM. Refer to the Testing and Adjusting, "Electronic Control Module (ECM) - Replace" in this manual.STOP
NOT OK - Voltage is greater than 10.0 0.5 DCV. The supply voltage is not correct. Proceed to Test Step 2.Test Step 2. CHECK SUPPLY CIRCUIT FOR A SHORT TO THE + BATTERY
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness from the Brake ECM.
At the machine harness connector for the Brake ECM, measure any voltage from connector contact J1-69 to frame ground. Expected Result:The voltage is 0.0 0.5 DCV.Results:
OK - Voltage is 0.0 0.5 DCV. The machine harness is correct. Proceed to Test Step 3.
NOT OK - Measured voltage is above 0.5 DCV. Battery or excessive stray voltage is present.Repair: The machine harness, for the 10V sensor power circuit, is likely shorted to +battery circuit. Repair or replace the machine harness. STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE
Inspect the harness connectors. Clean the contacts of the harness connectors. Check the wires for damage to the insulation that is caused by excessive heat, corrosion, or chafing. Reference: Refer to Testing and Adjusting, "Electrical Connector - Inspect" in this manual.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
Reconnect all harness connectors making sure that the connectors are fully seated and the clips for each connector are fastened.
Turn the disconnect switch and the key start switch to the ON position.
Use the Caterpillar Electronic Technician (ET) service tool, if available, to perform a "Wiggle Test" on the machine wiring harness. The wiggle test may detect intermittent shorts or opens in the machine