This is what I have on this code
good luck !
NOTE: For component location, see COMPONENT LOCATIONS. For connector terminal identification, see CONNECTOR IDENTIFICATION. For circuit identification and wiring diagram, see appropriate WIRING DIAGRAMS article.
NOTE: If Powertrain Control Module (PCM) is replaced, PCM must be reprogrammed. See POWERTRAIN CONTROL MODULE under PROGRAMMING. After each repair procedure has been completed, reconnect all components and perform POWERTRAIN VERIFICATION TEST VER-5 under VERIFICATION TESTS to ensure system is functioning properly.
NOTE: The Natural Vacuum Leak Detection (NVLD) pump system may also be referred to as the Leak Detection Pump (LDP) system. The NVLD Solenoid is an integral part of the NVLD Pump. NVLD Solenoid may also be referred to as the LDP Solenoid, and the NVLD Pressure Switch may also be referred to as the NVLD or LDP Switch.
DTC P0452: NVLD PRESSURE SWITCH STUCK CLOSED
Monitored & Set Conditions
The NVLD Switch is an integral part of the NVLD Pump. The NVLD Switch is monitored immediately after the engine has been started. The PCM activates the NVLD Solenoid. If PCM does not see NVLD Switch open, an error is detected and the DTC sets. This is a one-trip fault. See TRIP DEFINITION under ON-BOARD DIAGNOSTICS.
Possible Causes
? Good Trip Equal To Zero
? NVLD Switch Operation
? NVLD Pump
? Evaporative Emission (EVAP)/Proportional Purge Solenoid Leaks/Stuck Open
? EVAP Purge Solenoid Control Circuit Shorted To Ground
? NVLD Switch Signal Circuit Shorted To Ground
? PCM
Testing
1. Turn the ignition on, with the engine off. With the DRBIII(R), read DTCs and record the related Freeze Frame data. Is the Good Trip counter displayed and equal to zero? If yes, go to next step. If no, see INTERMITTENT FAILURES under ON-BOARD DIAGNOSTICS. 2. Turn the ignition off. Disconnect the EVAP Purge Solenoid harness connector. The EVAP Purge Solenoid may also be referred to as the Proportional Purge Solenoid. Turn the ignition on, with the engine off. Using a 12-volt test light, jump across the EVAP Purge Solenoid harness
connector. With the DRBIII(R), actuate the EVAP Purge Solenoid. Does the test light flash on and off? If yes, stop all actuations and go to next step. If no, stop all actuations and go to step 7.
NOTE: After disconnecting the EVAP Purge Solenoid vacuum hoses, inspect the hoses and solenoid for any signs of contamination from the EVAP Canister. This may indicate a faulty rollover valve. Repair/replace as necessary.
3. Turn the ignition off. Reconnect the EVAP Purge Solenoid harness connector. Disconnect the vacuum hoses at the EVAP Purge Solenoid. Using a hand vacuum pump, apply 10 in. Hg to the EVAP Canister side of the EVAP Purge Solenoid. Monitor the vacuum gauge for at least 15 seconds. Does the EVAP Purge Solenoid hold vacuum? If yes, go to next step. If no, replace the EVAP Purge Solenoid. 4. Turn the ignition on, with the engine off. Using the DRBIII(R), monitor the NVLD Switch State. Does the DRBIII(R) display the NVLD state OPEN? If yes, see INTERMITTENT FAILURES under ON-BOARD DIAGNOSTICS. If no, go to next step. 5. Turn the ignition off. Using the DRBIII(R), monitor the NVLD Switch State. Disconnect the NVLD Pump harness connector. Does the Switch change from CLOSED to OPEN? If yes, replace the NVLD Pump. If no, go to next step. 6. Disconnect the PCM harness connectors. Measure the resistance between ground and the NVLD Switch Signal circuit in the NVLD Pump harness connector. Is the resistance less than 5.0 ohms? If yes, repair the short to ground in the NVLD Switch Signal circuit. If no, check the PCM harness connector terminals for corrosion, damage or terminal push-out. Repair as necessary. If connector is okay, replace the PCM. 7. Turn the ignition off. Disconnect the PCM harness connectors. Measure the resistance between ground and the EVAP Purge Solenoid Control circuit at the EVAP Purge Solenoid harness connector. Is the resistance less than 5.0 ohms? If yes, repair the short to ground in the EVAP Purge Solenoid Control circuit. If no, check the PCM harness connector terminals for corrosion, damage or terminal push-out. Repair as necessary. If terminals are okay, replace the PCM.
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Tuesday, August 19th, 2008 AT 7:33 PM
