Possible Causes
GOOD TRIP EQUAL TO ZERO
NVLD SWITCH OPERATION
NVLD ASSEMBLY
(K52) EVAP PURGE SOL CONTROL CIRCUIT SHORTED TO GROUND
(K107) NVLD SWITCH SIGNAL CIRCUIT SHORTED TO GROUND
EVAP PURGE SOLENOID LEAKS/STUCK OPEN
PCM
DIAGNOSTIC PROCEDURE - P0452-NVLD PRESSURE SWITCH SENSE CIRCUIT LOW
| TEST | ACTION |
|---|---|
| 1 | Ignition on, engine not running. With the DRBIII®, read DTCs and record the related Freeze Frame data. Is the Good Trip Counter displayed and equal to zero?
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| 2 | Turn the ignition off. Disconnect the EVAP Purge Solenoid harness connector. Ignition on, engine not running. Using a 12-volt test light, jumper across the EVAP Purge Solenoid harness connector. With the DRBIII®, actuate the EVAP Purge Solenoid. Does the test light flash on and off?
|
| 3 |
NOTE:
After disconnecting the Evap Purge Solenoid vacuum connections, inspect the lines and solenoid for any signs of contamination from the EVAP Canister. This may indicate a faulty rollover valve. Replace/repair as necessary. Turn the ignition off.Disconnect the vacuum hoses at the Evap Purge Solenoid.Using a hand vacuum pump, apply 10 in Hg to the "CAN" of the EVAP Purge Solenoid.
NOTE:
Monitor the vacuum gauge for at least 15 seconds. Does the EVAP Purge Solenoid hold vacuum?
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| 4 | Ignition on, engine not running. Using the DRBIII®, monitor the NVLD Switch State. Does the DRBIII® display the NVLD state OPEN?
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| 5 | Turn the ignition on. Using the DRBIII®, monitor the NVLD Switch State. Disconnect the NVLD electrical connector. Does the Switch change from CLOSED to OPEN?
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| 6 | Turn the ignition off. Disconnect the NVLD electrical harness connector. Disconnect the PCM harness connector. Measure the resistance between ground and the (K107) NVLD Switch Signal circuit in the NVLD Assembly harness connector. Is the resistance below 5.0 ohms?
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| 7 | Turn the ignition off. Disconnect the EVAP Purge Solenoid harness connector. Disconnect the Powertrain Control Module harness connectors. Measure the resistance between ground and the (K52) EVAP Purge Sol Control circuit at the EVAP Purge Solenoid harness connector. Is the resistance below 5.0 ohms?
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