Circuit/System Testing
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Ambient and vehicle component temperature must be above 0°C (32°F) to command the switching valve or vacuum pump. This prevents erroneous results and damage to the EVAP leak detection pump assembly.
- Vehicle in Service Mode
- Disconnect the fuel tank vent pipe to the canister.
- Command the EVAP leak detection pump on for 1 min and record the pressure.
- Command the EVAP leak detection pump on and the switching valve to the pump position.
- Monitor the pressure over 5 s. It should decrease greater than 1.5 kPa (0.21 PSI).
- If pressure did not quickly decrease
Repair restriction in fuel tank vent pipe.
- Go to next step: If pressure quickly decreased
- If pressure did not quickly decrease
- Disconnect the line from the EVAP leak detection pump to the EVAP canister.
- Command the EVAP leak detection pump on for 1 min and record the pressure.
- Command the EVAP leak detection pump on and the switching valve to the pump position.
- Monitor the pressure over 5 s. It should decease greater than 1.5 kPa (0.21 PSI).
- If pressure did not quickly decrease
Repair the restriction in the line or EVAP canister.
- Go to next step: If no change in pressure
Go to next step: Replace the EVAP leak detection pump
- If pressure did not quickly decrease