NGC

P0452-EVAP PRESSURE SWITCH STUCK CLOSED





For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
Immediately after key off.

- Set Condition:
At key off, the PCM energizes the Purge Solenoid for a calibrated amount of time (30 seconds maximum) and stores the state of the ESIM switch. The state is evaluated again at the next key on. If the PCM does not detect that the ESIM switch is open, an error is detected. Two Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview

Diagnostic Test

1. VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
Ignition on, engine not running.
With a scan tool, select View DTC(s) and record the related Freeze Frame data if any DTC(s) are present.
Whether or not any DTC(s) are Active you will want to check the following items which may assist in repairing the customer's complaint successfully.
Check the vehicle's repair history.
If the vehicle has a repair history that pertains to the customer's current complaint, review the repair.
Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
Check for any service bulletin(s) related to the customer's complaint or DTC(s).
If a service bulletin applies, follow the instructions per the service bulletin.
Choose the following scenario that best applies.

The service bulletin repaired the customer's complaint.

- Testing complete.

A DTC is present, no service bulletins apply, or the service bulletin didn't repair the customer's complaint.

- Go to 2

2. DTC IS ACTIVE
NOTE: If the customer is experiencing an early fuel shut off during the fuel filling process along with P0440, P0441, and P0452 setting, you need to check for restrictions in the Evap Purge tubes/hoses as well as the Fresh Air Filter before continuing.

NOTE: Allow the vehicle to cool to ambient temperature before continuing with this procedure.

Start the engine.
Allow the engine to idle.
Using the scan tool, perform the ESIM FORCED MONITOR TEST.
Monitor the Evap System Monitor Switch state during the test.
Does the Evap System Monitor Switch state remain 'Closed' throughout the test?

Yes

- Go to 3

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking For An Intermittent DTC

3. EVAP SYSTEM MONITOR SWITCH STATE
With a scan tool, select Data Display and view the Evap System Monitor Switch state.
Disconnect the purge hose from the EVAP canister.
Does the Evap System Monitor Switch state change from 'Closed' to 'Open' when the purge hose was disconnected?

Yes

- Go to 4

No

- Go to 7

4. EVAP PURGE HOSE/TUBE AND FRESH AIR FILTER OBSTRUCTION
Turn the ignition off.
Inspect the Evap Purge hose/tube for proper routing and installation between the Evap Purge Solenoid and the Fuel Tank and between the Fuel Tank and the Evap Purge Canister.
Make sure the hose/tube and fresh air filter are not damaged, kinked, and free from any obstructions.
Check for any kink in the purge line connecting the LPV (Linear Purge Valve) to intake manifold.
Were any problems found?

Yes

- Repair or replace as necessary.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 5

5. (K52) EVAP PURGE CONTROL CIRCUIT SHORTED TO GROUND




Turn the ignition off.
Disconnect the C3 PCM harness connector.
Measure the resistance between ground and the (K52) Evap Purge Control circuit in the Evap Purge Solenoid harness connector.
Is the resistance below 100 ohms?

Yes

- Repair the (K52) Evap Purge Control circuit for a short to ground.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 6

6. EVAP PURGE SOLENOID
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Evap Purge Solenoid and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Verify that there is good pin to terminal contact in the Evap Purge Solenoid and the Powertrain Control Module connectors.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Replace the Evap Purge Solenoid.
- Perform the PCM Verification Test. Powertrain Verification Test

7. EVAP SYSTEM MONITOR SWITCH
With a scan tool, select Data Display and view the Evap System Monitor Switch state.
Disconnect the Evap System Monitor Switch electrical connector.
Does the Evap System Monitor Switch state change from CLOSED to OPEN when the switch is disconnected?

Yes

- Verify that there is good pin to terminal contact in the Switch and the Powertrain Control Module connectors. If OK, replace the ESIM Switch Assembly if no problems were found with the connectors.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 8

8. (K107) ESM SIGNAL SHORTED TO GROUND




Turn the ignition off.
Disconnect the C3 Powertrain Control Module (PCM) harness connector.
Measure the resistance between ground and the (K107) ESM Signal circuit in the Evap System Monitor Switch harness connector.
Is the resistance below 100 ohms?

Yes

- Repair the (K107) ESM Signal circuit for a short to ground.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 9

9. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Evap Purge Solenoid and the Powertrain Control Module (PCM) and between the Evap System Monitor Switch and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the ESIM, Evap Purge Solenoid, and the Powertrain Control Module connectors.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test. Powertrain Verification Test