RADIATOR & HYD OIL COOLER GP 3479292 - Caterpillar

Illustration 1 g02028153
Connections of the transmission shifter selector switchThis diagnostic code is associated with the transmission shifter selector 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 ECM. 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 961-BR) is shorted to ground while the "normally closed" signal circuit (wire 962-OR) 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 3381 FMI 04 is active before performing this procedure.
Table 1
Status of the Switch    
MODE    Switch Position    J2-35
961-BR Circuit    J2-40
962-OR Circuit    
Primary     Up     Open     Closed    
Secondary     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 - The continuity check agrees. Proceed to Test Step 2.
NOT OK - The continuity check does not agree. The switch has failed.Repair: Replace the switch. Verify that the new switch corrects the diagnostic code.STOPTest Step 2. CHECK THE SIGNAL CIRCUITS IN THE HARNESS FOR A SHORT.
Reconnect the switch to the machine harness.
Disconnect the J1 and J2 machine harness connectors from the ECU.
At the machine harness connector for the ECU, check for continuity between contact J2-35 (wire 961-BR) and contact J2-22 (wire 993-BR).
Press the switch. Release the switch and check for continuity.
At the machine harness connector for the ECU, check for continuity between contact J2-40 (wire 962-BR) and contact J2-22 (wire 993-BR).
Press the switch. Release the switch and check for continuity.Expected Result:The continuity check agrees with Table 1.Results:
OK - The continuity check agrees.Repair: Reconnect the machine harness connectors. Verify that the diagnostic code has been corrected. If the cause of the problem is not found, contact your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the ECU requires replacement, see