Circuit/System Description
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.
The evaporative emission (EVAP) system uses a EVAP leak detection pump to test for system leaks. The EVAP leak detection pump assembly consists of the following components:
- EVAP leak detection pump with reference orifice
- EVAP leak detection pump switching valve
- EVAP leak detection pump pressure sensor
The engine control module (ECM) monitors the pressure across the reference orifice with the EVAP leak detection pump pressure sensor. When all conditions are met, the ECM commands the vacuum pump ON and monitors the EVAP leak detection pump pressure sensor. If the ECM detects the pressure is not stabilized, the DTC will set.