966G Wheel Loader and 972G Wheel Loader Power Train Caterpillar

CID 0444 FMI 03 Magnetic Switch (Start Relay) Voltage Above Normal - Test

Usage:

972G 1EW

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Illustration 1	g00436098
Start Relay Magnetic Switch Schematic

CID 0444 FMI 03 service code is recorded when the power train electronic control module (ECM) reads the voltage of the start relay circuit as above normal (short to +battery).

Note: Ensure that the service code CID 0444 FMI 03 for the start relay is active. Before performing this procedure, refer to table 1 in order to determine the connector contact number and the wire number that corresponds to the failed circuit.

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Table 1
Relay Information
Fault	Connector Contact No.	Wire No.
Starter Relay	J1-8 ⁽¹⁾	306-GN

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^( 1 )

Connector contact number of the ECM.

Note: All start relay return lines are joined and connect to contacts J1-7 and J2-3 (wire 975-WH) of the power train ECM.

Note: The approximate coil resistance of the start relay is 15 to 65 Ohms.

Check the start relay signal circuit for a short to the +battery.
1. Turn the key start switch and the disconnect switch to the OFF position.
1. Disconnect the machine harness from the suspected start relay.
1. Disconnect the machine harness connectors J1 and J2 from the power train ECM.
1. At machine harness connector J1 and J2, measure the resistance from the start relay signal contact (refer to table 1) to all possible sources of +battery. The possible sources of positive voltage are connector contacts J1-1, J1-4, J1-6, J1-8, J1-10, J1-11, J1-12, J1-17, J1-18, J1-40, J2-1, J2-2, J2-7, J2-8, J2-13, J2-19 and J2-37.
  Expected Result: Each resistance should be greater than 5000 ohms.
  Results:
  - OK - The machine harness is correct. Proceed to Step 2.
  - NOT OK - There is a short in the machine harness. The short is between the start relay signal contact (refer to table 1) and the circuit with low resistance measurement. Repair the machine harness or replace the machine harness. STOP.

Check if the fault is still present.
1. Inspect the contacts and clean the contacts of the harness connectors.
1. Reconnect all harness connectors.
1. Turn the disconnect key and the key start switch to the ON position.
1. Enter Service Mode of the Caterpillar Monitoring System. Clear all inactive faults.
1. Attempt to operate the machine in all gears. All gears may not be available.
1. Stop the machine and engage the parking brake.
1. Check to see if CID 0444 FMI 03 service code for the start relay is active.
  Expected Result: The CID 0444 FMI 03 service code for the start relay is active.
  Results:
  - YES - The fault has not been corrected. It is unlikely that the power train ECM is faulty. Perform the previous steps again. If the cause of the fault is not found, replace the power train ECM. Refer to Testing and Adjusting, "Electronic Control Module (Power Train) - Replace" for more information on replacing the power train ECM. STOP.
  - NO - Fault is NOT active. The fault does not exist at this time. The initial fault was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation. STOP.