Conditions for Clearing the MIL/DTC
WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
- The DTC becomes history when the conditions for setting the DTC are no longer present.
- The history DTC clears after 40 malfunction free warm-up cycles.
- The PCM receives a clear code command from the scan tool.
DTC P0621
| Step | Action | Value | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Starting and Charging Schematics 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 |
|
- | Go to TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS in Wiring Systems | Go to Step 3 |
| 3 |
|
5.0 V | Go to Step 5 | Go to Step 4 |
| 4 | Test the generator turn on signal circuit for a short or open. Refer to CIRCUIT TESTING
and WIRING REPAIRS
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 8 | Go to Step 6 |
| 5 | 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 8 | Go to Charging System Test |
| 6 | Inspect for poor connections at the harness connector of the PCM. Refer to TESTING FOR INTERMITTENT CONDITIONS AND POOR CONNECTIONS
and CONNECTOR REPAIRS
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 8 | Go to Step 7 |
| 7 |
IMPORTANT:
The replacement PCM must be programmed. Replace the PCM/ECM. Refer to: POWERTRAIN CONTROL MODULEIs action complete? |
- | Go to Step 8 | - |
| 8 |
|
- | Go to Step 2 | System OK |