GASKET 4844689 - Caterpillar

Illustration 1 g02557736
System voltage connectionsThe CID 0168 diagnostic code is associated with the machine system voltage that is supplied to the Implement ECM. The FMI 03 means that the ECM has detected that the system voltage is above normal. The ECM activates this diagnostic code when the system voltage is above 32.0 VDC.The possible causes of this diagnostic code are listed below:
The alternator output is above normal.
The ECM has failed or the operating software is not the latest version. ECM failure is the least likely cause. The Implement ECM is one of the components that is included in the Battery Management System. Power is supplied to these components through a fuse in the lower panel right column when the Low Current Mode Relay is energized. This relay along with the Main Power Relay are controlled by the Relay Driver Module according to instructions that are received by the Machine ECM. None of the components in the Battery Management System can cause an above normal system voltage.Note: If the Transmission ECM or other control modules on the machine have all activated a CID 0168 FMI 03 diagnostic code for system voltage, the most likely cause is a problem with the system voltage supply that is provided by the alternator.Test Step 1. CHECK THE SYSTEM VOLTAGE AT THE ECM
Turn the disconnect switch and the key start switch to the OFF position.
At the J1 harness connector for the Implement ECM, use the 7X-1710 Multimeter Probes to measure the supply voltage. Insert the positive probe along one of the positive power supply circuit wire at contact J1-31 (wire 133-RD). Insert the negative probe along one of the supply return circuit wires at contact J1-13 (wire 299-BK).
Start the engine and run the engine at high idle.
Measure the voltage between contact J1-31 and contact J1-13.Expected Result:The voltage measurement is in the range of 18.0 VDC to 32.0 VDC.Results:
OK - The voltage measurement of the ECM power supply is in the range of 18.0 VDC to 32.0 VDC. The system voltage is correct. There does not appear to be a problem with the alternator or the machine power supply circuits. Proceed to Test Step 2.
NOT OK - The voltage measurement of the ECM power supply is greater than 32.0 VDC.Repair: The operation of the alternator is not correct. Refer to Service Manual, SENR4130, "HDB Series and M1 Series Heavy Duty Brushless Alternators" for brushless alternators for further testing and repair procedures for the alternator or change the alternator.STOPTest Step 2. CHECK THE STATUS OF THE DIAGNOSTIC CODE
Turn the disconnect switch and key start switch to the OFF position.
Reconnect any harness connectors that were disconnected and checked.
Turn the disconnect switch and the key start switch to the ON position.
Start the engine and run the engine at high idle.
Determine if the CID 0168 FMI 03 diagnostic code is active.Expected Result:The CID 0168 FMI 03 diagnostic code is not active.Results:
OK - The CID 0168 FMI 03 diagnostic code is not active. The diagnostic code does not exist at this