TORQUE CONVERTER GP 1639362 - Caterpillar

Illustration 1 g01166126
Schematic of the Primary Steering Pressure Switch
CID 0793 FMI 03 diagnostic code can only be recorded if the optional secondary steering system is installed. The primary steering pressure switch is connected to two inputs of the ECM. One contact is open and the other contact is grounded during proper operation.This FMI 03 means that the ECM has determined that both contacts are open.
Table 1
Primary Steering Pressure Switch
Switch Position 417-GY(Grey) Circuit
N/O
J2-10 484-YL(Yellow) Circuit
N/C
J2-6
Low Pressure Open Closed
High Pressure Closed Open Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code is corrected.Note: Ensure that the diagnostic code indicator is active and that the diagnostic code is active.Test Step 1. CHECK THE GROUND CIRCUIT OF THE SWITCH IN THE HARNESS
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector(s) from the ECM.
Measure the resistance between contact A (wire 201-BK(Black)) and cab ground. Expected Result:The resistance is less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. The circuit is correct. Proceed to Test Step 2.
NOT OK - The resistance is greater than 5000 ohms. The circuit is open. The machine harness has failed.Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE SWITCH CIRCUITS FOR A SHORT TO THE +BATTERY CIRCUIT
The machine harness connector(s) remains disconnected from the ECM.
The disconnect switch and the key start switch remain in the OFF position.
Disconnect the 6 pin connector for the switch from the machine harness.
At the machine harness connector for the ECM, measure the resistance from contact J2-6 (wire 484-YL(Yellow)) and contact J2-10 (wire 417-GY(Grey)) of the machine harness to all the contacts that are used in the machine harness connectors for the ECM. Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
YES - Each resistance measurement is greater than 5000 ohms. The harness is correct. Proceed to Test Step 3.
NO - One or more of the measurements were less than 5 ohms. There is a short in the machine harness.Repair: The short is between wire 484-YL(Yellow) and the circuit with the lowest resistance measurement, or the short is between wire 417-GY(Grey) and the circuit with the lowest resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK THE SWITCH CIRCUITS IN THE HARNESS
The machine harness remains disconnected from the ECM and the switch.
At the harness connector for the switch, connect a jumper wire between contact C (wire 484-YL(Yellow)) and contact B (wire 417-GY(Grey)).
At the harness connector for the ECM, measure the resistance from contact J2-6 (wire 484-YL(Yellow)) to contact J2-10 (wire 417-GY(Grey)). Expected Result:The resistance is less than 5 ohms.Results:
OK - The resistance is less than 5 ohms. Proceed to Test Step 4.
NOT OK - The resistance is greater than 5000 ohms. The circuit is open.Repair: The machine harness has failed. Repair the machine harness or replace the machine harness.STOPTest Step 4. CHECK THE OPERATION OF THE SWITCH (LOW PRESSURE)Note: