VIN Range: G00442->G45703

Engine Emission Control - VIN Range: G00442->G45703

1. Verify the customer concern by operating the system.
2. Visually inspect for obvious signs of mechanical or electrical damage.
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. If the concern is not visually evident, refer to the Symptom Chart.

Diagnostic Trouble Code (DTC) P0400 indicates exhaust gas recirculation (EGR) system flow malfunction.

Possible Source(s):
- Exhaust manifold to EGR valve pipe tube blocked.
- Exhaust manifold to EGR valve pipe tube cracked.
- EGR valve stuck closed.
- EGR valve stuck open.
- EGR valve loose.
- Fuse 37 in the front power distribution box (FPDB).
- Relay 5 in the FPDB
- Electrical harness.
- Electrical connector(s)
Action(s) to take:
- GO to Pinpoint Test A.

Diagnostic Trouble Code (DTC) P0405 indicates exhaust gas recirculation (EGR) valve malfunction, short to battery/12volts (V).

Possible Source(s):
- Electrical harness.
- Electrical connector(s).
- Engine control module (ECM).
- EGR valve.
Action(s) to take:
- GO to Pinpoint Test B.

Diagnostic Trouble Code (DTC) P0406 indicates exhaust gas recirculation (EGR) valve malfunction, short to ground/open circuit.

Possible Source(s):
- Electrical harness.
- Electrical connector(s).
- ECM.
- EGR valve.
Action(s) to take:
- GO to Pinpoint Test C.