HOUSING 8W7452 - Caterpillar

The Electronic Control Module (ECM) monitors the temperature at the intake of the Diesel Particulate Filter (DPF).Probable Causes
Diagnostic codes
Incorrect wiring for temperature sensors
Insulation on the exhaust duct (if equipped)
Exhaust leaks
WastegateRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps    Values    Results    
1. Diagnostic Codes
A. Establish communication between the electronic service tool and the Electronic Control Module (ECM).
B. Check for active diagnostic codes.
   
Codes
   
Result: A diagnostic trouble code is active or logged.
Repair: Troubleshoot any diagnostic codes before continuing with this procedure.
Result: A diagnostic trouble code is not active or logged.
Proceed to Test Step 2.
   
2. Incorrect Wiring for Temperature Sensors
A. Check that the Diesel Oxidation Catalyst (DOC) inlet temperature sensor and DPF inlet temperature sensor wiring has not been switched.
Note: The engine may run without indicating a fault for many hours with this condition.
B. Check that the wiring for the DOC inlet temperature and the DPF inlet temperature sensor is connected to the correct ECM pins.
Refer to the Electrical Schematic for the application.
   
Wiring    
Result: The wiring for the DOC inlet temperature sensor or the DPF inlet temperature sensor is incorrect.
Repair: Repair the faulty wiring or replace the faulty wiring.
Result: The wiring for the DOC inlet temperature sensor and the DPF inlet temperature sensor is OK.
Proceed to Test Step 3.    
3. Insulation on the Exhaust Duct (If Equipped)
A. Check the insulation on the exhaust duct between the engine and the Clean Emissions Module (CEM). Make sure that insulation is not missing or damaged.
   
Insulation
   
Result: The insulation is missing or damaged.
Repair: Repair or replace the insulation on the exhaust duct.
Result: The insulation is OK.
Proceed to Test Step 4.
   
4. Exhaust Leaks
A. Thoroughly inspect the exhaust duct between the engine and the CEM for leaks. Ensure that all connections are secure and no leaks are present.
   
Exhaust leaks
   
Result: There are exhaust leaks.
Repair: Make the necessary repairs, Verify that the repair has eliminated the fault.
Result: The exhaust duct is OK.
Proceed to Test Step 5.
   
5. Wastegate
A. Check for correct operation of the wastegate. Refer to Systems Operation, Testing, and Adjusting, "Turbocharger - Inspect".
   
Wastegate
   
Result: The wastegate or the wastegate actuator is faulty.
Repair: Install a replacement turbocharger. Refer to Disassembly and Assembly, "Turbocharger - Remove" and Disassembly and Assembly, "Turbocharger - Install".
Result: The wastegate and the wastegate actuator are OK.
Contact the Dealer Solution Network (DSN).