Question about 1999 GMC Suburban
Code P0452 - Evaporative Emission Control System
Pressure Sensor Low Input
From the TSB's...
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.
? 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
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.
Code P0453 Fuel Tank Pressure Sensor.
Check the wires between the pcm and the fuel tank pressure sensor.At the sensor with it disconnected (key on) you should have ground on the black wire and 5 volts on the gray wire.
Posted on May 16, 2010
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
New users get 2 Free calls (no credit card required) and instant help on almost anything you can think of (from cars to computers, appliances, handyman, and even pets).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
May 01, 2015 | Cars & Trucks
Mar 09, 2014 | 1998 GMC Safari
Aug 04, 2011 | 2000 Chevrolet Blazer
Feb 02, 2011 | 2001 Chevrolet Blazer
Mar 09, 2010 | 2000 Buick Park Avenue
Dec 12, 2009 | 2000 Oldsmobile Bravada
Jan 07, 2009 | 1998 Chevrolet Malibu
559 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: