| WARNING | Read service precautions before proceeding with service procedure. See SERVICE PRECAUTIONS . |
| CAUTION | If Engine Control Module (ECM) replacement is instructed in following test, always ensure ECM electrical connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
Based on input signals from heated oxygen sensor and purge flow switching valve Vacuum Switching Valve (VSV), the ECM determines if a fuel leak exists inside the fuel tank. DTC is set when purge flow switching valve VSV is on and vapor density of air flowing from EVAP VSV into the intake manifold is high. Possible causes are
- Defective fuel tank.
- Defective ECM.
