Symptoms:
- The exhaust back pressure regulator will be disabled, in either a closed or open position
- Reduced engine performance and insufficient turbocharger pressure
- The check engine warning light with be illuminated
Causes:
- Damaged electrical wiring and connectors
- Shorted or open exhaust back pressure sensor harness
- Faulty PCM, in very rare cases
Possible Solutions:
- Clearing or replacing a clogged back pressure tube
- Replacing or cleaning a faulty exhaust back pressure sensor
- Replacing or repairing a shorted or open exhaust back pressure sensor
- Manually test individual circuits within the exhaust back pressure system, and replace any faulty components
- In rare cases, replacing a faulty PCM