SHAFT-BEVEL 5G4722 - Caterpillar

Illustration 1 g01943643
Connections of the lockup clutch disable switch
This diagnostic code is associated with the lockup clutch disable switch. The FMI 04 is recorded when the ECU determines that the voltage is below normal for the circuit. The switch has two inputs to the ECU. During normal operation, one of the inputs is open. The other input is grounded. When a circuit is measured with a voltmeter, an open circuit will measure approximately 8 VDC to ground and a closed circuit will measure approximately 0 VDC to ground. The possible causes of this diagnostic code are listed:
The "normally open" signal circuit (wire Y985-BR(Brown)) is shorted to ground while the "normally closed" signal circuit (wire Y988-BR(Brown)) is shorted to ground.
The switch has failed.
The ECU has failed. This is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all of the connections in the circuit are clean and secure. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.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 3013 FMI 04 is active before performing this procedure.
Table 1
Status of the Switch
MODE Switch Position J1-41
Y985-BR(Brown) Circuit J2-23
Y988-BR(Brown) Circuit
Enabled Lockup Clutch Up Open Closed
Disabled Lockup Clutch Down Closed Open Test Step 1. CHECK THE SWITCH.
Disconnect the switch from the machine harness.
Check for continuity between contact A and contact B of the switch.
Press the switch. Release the switch and check for continuity.
Check for continuity between contact B and contact C of the switch.
Press the switch. Release the switch and check for continuity. Expected Result:The continuity check agrees with Table 1.Results:
OK