This post show you the steps on how to solve Detroit EPA07 GHG14 engine regeneration DOC inlet temperature unable to reach HC dosing temperature.
This instruction should only be completed if directed here from Regeneration troubleshooting.
Verification: Verify Parked Regeneration Completes
Note : Complete steps in numerical order. If any of the items below have been previously inspected during this visit, do not inspect a second time.
1.Connect using DiagnosticLink .
2.Are any of the following fault codes present?
- SPN 3246/FMI 0 DPF Outlet Temp very high
- SPN 3250/FMI 0 DOC Outlet Temp very high
- SPN 3251/FMI 0 DPF Filter Pressure Out of Range Very High
- SPN 3480/FMI ALL Hydrocarbon (HC) Doser Fuel Supply Pressure
- SPN 3556/ FMI ALL Regen Temperature out of range
- SPN 188/ FMI 31 Idle Speed is Higher than Targeted Idle Speed
- SPN 51/FMI 2 Intake Throttle Position deviation error
- SPN 3711/FMI 31 High Idle Regen (aborted) – Low Exhaust Temp
- SPN 3713/FMI 14 High Idle Regen (aborted) – Low Regen Temp
- SPN 4077/FMI ALL Hydrocarbon (HC) Doser Fuel Line Pressure
2a Yes; perform the troubleshooting for the fault code.
2bNo; Go to step 3.
3.Using DiagnosticLink (Key ON, Engine OFF), is the barometric pressure reading between 68 and 110 kPa (10 and 16 psi)?
3a Yes; Go to step 4.
3b No; install an MCM and retest.
4.Compare the inlet manifold pressure (IMP) and barometric pressure reading. Are the readings within 0.10 bar (1.5 psi) of each other?
4a Yes; Go to step 8.
4b No; replace the inlet manifold pressure sensor.
5.Inspect for plugged ports in the EGR Venturi Pipe. Are the EGR Venturi Pipe ports plugged?
5a Yes; clean ports using procedure in 14 TS-2.
5b No; Go to step 6.
6.Inspect complete exhaust system for leaks. Are there exhaust leaks before the ATD?
6a Yes; repair as needed.
6b No; Go to step 7.
7.Inspect entire air intake system including the Charge Air Cooler (CAC) for loose clamps, leaks and/or restrictions (Refer to OEM). Are any leaks or restrictions present?
7a Yes; repair as necessary.
7b No; Go to step 8.
Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.
- Always start and operate an engine in a well ventilated area.
- If operating an engine in an enclosed area, vent the exhaust to the outside.
- Do not modify or tamper with the exhaust system or emission control system.
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.
To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.
8.Run engine at 1200 rpm for 10 minutes.
9.Monitor DOC inlet and outlet temperatures. Are the temperatures within 25°C (45°F) of each other?
9a Yes; Check valve lash and engine brake rocker lash. If either is out of adjustment, readjust the lash, perform a parked regeneration, and continue with the initial diagnostics that directed you to DOC inlet temperature will not reach HC dosing temperature.
9b No; Go to step 10.
10.Disconnect DOC Outlet Temperature Sensor and inspect connector for damaged, bent, spread, or corroded pins. If Temperature Sensor connector is OK, check connections upstream of the MCM (ATD harness 10-pin connector pin 5, VIH 31-pin connector pin 17, and MCM 120-pin connector pin 29). Is damage found?
10a Yes; repair connector as necessary perform a parked regeneration, return and continue with the initial diagnostics that directed you to DOC inlet temperature will not reach HC dosing temperature.
10b No; replace the DOC Outlet Temperature Sensor, perform a parked regeneration, return and continue with the initial diagnostics that directed you to DOC inlet temperature will not reach HC dosing temperature.
More repair cases for Detroit Diesel engines,please refer to:Detroit Diesel Engine Repair