Conditions for Clearing the DTC
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- The Conditions for Setting the DTC are no longer present.
- A history DTC will clear after 40 malfunction free ignition cycles.
- The engine control module (ECM) receives the clear code command from the scan tool.
DTC P0622 (Diesel Engine)
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Starting and Charging Schematics (Except HP2)
or Starting and Charging Schematics (HP2) Connector End View Reference: Engine Electrical Connector End Views |
||||
| 1 | Did you perform the Engine Electrical Diagnostic System Check? | - | Go to Step 2 | Go to Diagnostic System Check - Engine Electrical |
| 2 | Test the generator field duty cycle signal circuit for a short or open. Refer to Circuit Testing
andWiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 6 | Go to Step 3 |
| 3 | Inspect for poor connections at the harness connector of the generator. Refer to Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 6 | Go to Step 4 |
| 4 | Inspect for poor connections at the harness connector of the PCM/ECM. Refer to Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 6 | Go to Step 5 |
| 5 |
IMPORTANT:
The replacement PCM/ECM must be programmed. Replace the PCM/ECM. Refer to Engine Control Module (ECM) Replacement
in Engine Controls-6.6L.Did you complete the repair? |
- | Go to Step 6 | - |
| 6 |
|
- | Go to Step 2 | System OK |