MUFFLER-EJCTR-YM 3607879 - Caterpillar

The possible causes of this problem are listed below:
The signal wire (334-BU(Blue)) is shorted to the +battery circuit.
The relay for the Air inlet heater has failed.
The ECM has failed. This is unlikely. This failure causes the lifetime of the heater element to be shortened. Also, the battery will be excessively drained. A diagnostic code of CID 0168 FMI 04 may be active at this time. Note: Also, ensure that the disconnect switch is OFF when the +battery connections at the relay for the air inlet heater are connected or disconnected.Test Step 1. CHECK THE RELAY CIRCUIT FOR A SHORT TO THE +BATTERY CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the relay for the air inlet heater.
Disconnect the J1 and J2 machine harness connectors from the ECM.
At machine harness connector J2, measure the resistance from the J2-8 (relay signal) to all possible sources of +battery. The possible sources of positive voltage are 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, J2-13, J2-19, and J2-37. Expected Result:Each resistance should be greater than 5000 ohms.Results:
OK - The machine harness is correct. The relay contacts have failed or the ECM has failed. Proceed to test step 2.
NOT OK - There is a short in the machine harness. The harness has failed.Repair: The short is between wire 334-BU(Blue) (relay signal) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK THE RELAY CONTACTS FOR A SHORT.
The disconnect switch and the key start switch remain in the OFF position.
The ECM and the relay remain disconnected from the machine harness.
Disconnect 101-RD(Red) (+battery) and 160-BU(Blue)(heater) from the relay.
At the terminals of the relay, measure the resistance from one terminal to the other terminal. Expected Result:The resistance should be greater than 5.0 ohms (NO continuity). Results:
OK - The resistance that is measured is greater than 5 ohms. The relay contacts are correct. Proceed to test step 3.
NOT OK - The resistance that is measured is less than 5 ohms. The internal contacts of the relay have failed.Repair: Replace the relay for the air inlet heater.STOPTest Step 3. CHECK IF THE PROBLEM IS STILL ACTIVE.
Inspect the contacts and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Start the engine. Expected Result:The air inlet heater is functioning correctly.Results:
YES - The air inlet heater is functioning correctly.Repair: The problem does not exist at this time. The initial problem 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 problem has not been corrected. The ECM has failed.Repair: It is unlikely that the ECM has failed. Perform the previous test steps again. Exit this procedure and perform the diagnostic code procedure again. If the problem persists, the ECM may have failed. Prior to replacing an ECM, always contact your dealership's Technical Communicator for possible consultation