Circuit/System Verification

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Ignition/Vehicle - Off
Verify the following conditions do not exist:
- Q12 Evaporative Emission Canister Purge Solenoid Valve - Incorrect connection/Incorrect installation/Leaking/Visible Damage
- Vacuum Hoses @ Q12 Evaporative Emission Canister Purge Solenoid Valve - Incorrect connection / Incorrect installation/Incorrect routing
- If a condition exists
  Repair or replace as necessary
- Go to next step: If no condition exists
Ignition - On / Vehicle - In Service Mode
Verify DTC P0451 - P0454 is not set.
- If any of the DTCs are set
  Refer to: DTC P0451-P0454
- Go to next step: If none of the DTCs are set
Engine - Idling
Perform the scan tool control function: Evaporative Emission Canister Vent Valve - Not Venting
Verify the scan tool parameter: Fuel Tank Pressure Sensor = Greater than -9.3 mmHg (-5.0 in. H2O) - After 60 s
- If -9.3 mmHg (-5.0 in. H2O) or less
  Test or replace the component: Q12 Evaporative Emission Canister Purge Solenoid Valve
- Go to next step: If -9.2 mmHg (-4.9 in. H2O) or greater
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set.
- If the DTC sets
  Repeat the procedure starting at step 2
- Go to next step: If the DTC does not set
All OK.