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Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, 2002 Chevrolet Monte Carlo, and 2002 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Are there any MAP DTCs set? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Inspect the exhaust system for modification of original installed parts or leaks. Repair the exhaust system as necessary if you locate a problem. Did you find and correct the condition? If yes, go to step  7. If no, go to next step.
  4. Inspect the EGR valve gasket and pipe for leaks. If you locate a problem, clean or replace the EGR system components as necessary. Did you find and correct the condition? If yes, go to step  7. If no, go to next step.
  5. Remove the EGR valve. Inspect the following components for leaks and restrictions: The EGR pintle and EGR valve passages. Did you find and correct the condition? If yes, go to step  7. If no, go to next step.
  6. Remove the EGR inlet pipe from the exhaust manifold. Inspect the manifold EGR ports and the EGR inlet pipe for a blockage caused by excessive deposits or other damage. Did you find and correct the condition? If yes, go to next step. If no, DIAGNOSTIC AIDS .
  7. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  8. With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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