KIT-ENGINE OVERHAUL 20R1431 - Caterpillar

Illustration 1 g01004093
Schematic Of The Magnetic Switch (Air Inlet Heater Relay)This diagnostic code is recorded when the ECM reads the voltage of the relay circuit as being above normal or shorted to +battery.The possible causes of this diagnostic code are listed:
The circuit of the relay is shorted to +battery.
The ECM has failed. This is unlikely. Note: Ensure that CID 0617 FMI 03 is active.System Response:When this diagnostic code occurs, a warning is shown on the monitor. The diagnostic code will cause the air inlet heater to be turned ON all the time.Test Step 1. CHECK THE RELAY CIRCUIT FOR A SHORT TO +BATTERY.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the relay.
Disconnect machine harness connector J1 and machine harness connector J2 from the ECM.
At the machine harness connector, measure the resistance from signal contact J2-5 (wire 310-PU) to all possible sources of +battery. Expected Result:Each resistance measurement should be greater than 5000 ohms. Results:
OK - Each resistance measurement is correct. The machine harness is correct. Proceed to test step 2.
NOT OK - One or more resistance measurements are not correct. Repair: There is a short in the machine harness. The short is between signal contact J2-5 (wire 310-PU) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Inspect the contacts of the harness connectors and clean the contacts.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Enter the service mode of the Caterpillar Monitoring System and clear all inactive diagnostic codes.
Operate the machine.
Check if CID 0617 FMI 03 is present.Expected Result:CID 0617 FMI 03 for the relay is NOT present. Results:
YES - The diagnostic code is NOT present. The diagnostic code does not exist at this time. The initial diagnostic code 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
NO - The diagnostic code has not been corrected.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". STOP