Diagnostic Aids
WARNING: This page is about a different variant/trim than selected.
- A restriction in the EVAP canister or vent lines that keeps the fuel tank pressure and EVAP leak detection pump sensor from comparing each others value.
- A switching valve stuck in the vent position will affect performance.
- Ensure that the reference port on the fuel tank pressure sensor is unobstructed.
- A fuel tank pressure sensor that is skewed or does not have a linear transition from low to high may cause these DTC's to set. Scan tool output controls and Review Stored Data can help detect erratic sensor response. To test the sensor signal under vacuum conditions, use Review Stored Data and the EVAP Test function to capture data while commanding purge to 20%, then review stored data to look for erratic sensor operation. A similar test can be done for the pressure side of the sensor operation by applying pressure with the GE-41413-A while taking a snapshot.