RING-EXPANDER 1841689 - Caterpillar

Illustration 1 g00547099
Schematic of the Solenoid Valve (Exhaust Diverter) This diagnostic code is recorded when the ECM reads the voltage of the solenoid circuit as above normal (short to +battery).Possible causes of this diagnostic code are listed:
When the exhaust diverter switch is in the automatic position, wire 987-WH is shorted to the + battery.
Wire M728-WH shorted to the + battery and the bed is down.
The ECM has failed.Ensure that the CID 1394 FMI 03 for the solenoid is active.System Response:The exhaust is diverted to the muffler at incorrect times.Test Step 1. CHECK THE SOLENOID CIRCUIT FOR A SHORT TO THE + BATTERY.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the solenoid valve.
Disconnect the machine harness connectors J1 and J2 from the ECM.
Place the switch in the automatic mode. At machine harness connector J1 and J2, measure the resistance from the signal contact J1-17 (wire M728-WH) to all possible sources of +battery. The possible sources of positive voltage are contacts: J1-1, J1-6, J1-8, J1-11, J1-12, J1-18, J2-1, J2-8, J1-13, J2-19 and J2-37. Expected Result:Each resistance should be greater than 5000 ohms.Results:
YES - Each resistance is greater than 5000 ohms. The machine harness is correct. Proceed to test step 2.
NO - There is a short in the machine harness. Repair: The short is between the signal contact J1-17 (wire M728-WH) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness. Stop.Test Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Inspect the contacts and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Clear all inactive diagnostic codes.
Attempt to operate the machine in all of the gears.Note: All of the gears may not be available.
Stop the machine and engage the parking brake.
Check if the diagnostic code for the solenoid valve is present.Expected Result:The diagnostic code for the solenoid valve is NO longer 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. Also, recheck if the diagnostic code is active. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". Stop.