ENGINE AR-D 7C2491 - Caterpillar

Note: This procedure will require removal of some of the Inverter Cabinet compartment covers. Once this problem is resolved, the Inverter Cabinet compartment covers that were removed must be installed. Ensure that all the Inverter compartment covers are installed. Ensure that all the cover bolts are securely tightened to seal the cabinet from outside contamination.Test Step 1. PERFORM THE POWER TRAIN ELECTRIC DRIVE SYSTEM SERVICE SHUTDOWN PROCEDUREWhen an area that contains high-voltage components on the machine must be entered, the Power Train Electrical System Service Shutdown procedure must be performed before the initial removal of any cabinet compartment cover and after the engine has been operated.Reference: Refer to the Troubleshooting, "Electrical Shutdown and Voltage Discharge" section of this manual. Perform the "Power Train Electrical System Service Shutdown" procedure to verify that the voltage in the power train system has been discharged. Once the voltage of the DC bus in the Inverter Dynamic Retarding Contactor compartment is verified as discharged, and a jumper wire is in place, return to this point in this procedure and proceed.Results:
OK - The Power Train Electrical System Service Shutdown procedure has been performed, the voltage is verified as discharged, and the jumper wire is in place. Proceed to the next test step.Test Step 2. CHECK THE CURRENT SENSOR CIRCUITS FOR A SHORTThe key start switch and the battery disconnect switch must be in the OFF position.
Remove the cabinet compartment cover from the compartment that contains the Motor 2 ECM.
Disconnect the harness connector J2 from the Motor 2 ECM.
Illustration 3 g06171019
Compartment for Current Phase Sensors
(4) Motor 2 Phase Current sensor - left to right: M2B CT, M2A CT, M2C CT
(5) Generator Phase Current sensor - left to right: GENA CT, GENB CT, GENC CT
(6) Motor 1 Phase Current sensors - left to right: M1C CT, M1A CT, M1B CT
Remove the cover (3) from the cabinet compartment that contains the M2B CT sensor.
Use the high-voltage meter to measure for DC voltage between all the motor phase bus bars and all the Generator phase bus bars. Verify that there is less than 50.0 VDC between the bus bars. Once the voltage is verified, continue to the next step.
At the harness connector J2, measure the resistance between the sensor signal (+) contact J2-24 (wire IV2-BK(Black)) and all the other circuit contacts that are used in the J2 harness connector.
At the harness connector J2, measure the resistance between the sensor signal (+) contact J2-6 (wire IV2N-BK(Black)) and all the other circuit contacts that are used in the J2 harness connector.Expected Result:Each resistance measurement between the sensor signal circuits and each of the other circuits in the J2 connector measure greater than 4000 ohms.Results:
OK - The resistance measurements are indicating that the current sensor circuits are not shorted to any other circuit in the ECM J2 connector. Proceed to the Test Step 3.
NOT OK - At least one or more of the resistance measurements between a current sensor signal circuit and another circuit is less than 4000 ohms. The low resistance