AMMETER AS 1351919 - Caterpillar

Illustration 1 g01126441
Schematic of the Primary Steering pressure switch
This diagnostic code is associated with the Primary Steering pressure switch. An FMI 04 means the ECM has determined the voltage on the Primary Steering pressure switch circuit is below normal. Possible causes of this diagnostic code are:
Both contacts are closed at the same time.
One contact is shorted to a ground source.Note: The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected.Ensure that the diagnostic code of CID 0793 FMI 04 is active before performing this procedure.Test Step 1. CHECK THE SWITCH
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the Primary Steering switch.
Turn the key start switch and the disconnect switch to the ON position. Expected Result:The CID 0793 FMI 04 has been replaced by CID 0793 FMI 03.Results:
OK - The CID 0793 FMI 04 has been replaced by CID 0793 FMI 03. The machine harness and the ECM are correct. Proceed to Test Step 3.
NOT OK - The CID 0793 FMI 04 is still active. Proceed to Test Step 2.Test Step 2. CHECK THE HARNESS
Turn the disconnect switch and the key start switch to the OFF position.
The machine harness remains disconnected from the switch.
Disconnect the J2 and J1 harness connectors from the machine ECM.
Measure the resistance between contacts J2-37 (wire 417-GY(Grey)) and J2-38 (wire 484-YL(Yellow)) of the machine harness to all the contacts that are used in machine harness connectors for the ECM. Expected Result:Each resistance measurement is greater than