LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 102 (Engine Controls - Self-Diagnostics - 3.5L) >> Diagnostic Tests >> DTC P0401: EGR Flow Insufficient >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue and 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. If any MAP DTCs are set, repair DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no MAP DTCs are set, go to next step.
  3. Check exhaust system for leaks and modification of original parts. If any problems are found, repair as necessary. After repairs, go to step  7. If no problems are found, go to next step.
  4. Check EGR valve gasket and pipes for leaks. If any problems are found, repair EGR system as necessary. After repairs, go to step  7. If no problems are found, go to next step.
  5. Remove EGR valve. Check EGR valve pintle and passages for leaks and/or restrictions. If any problems are found, repair as necessary. After repairs, go to step  7. If no problems are found, go to next step.
  6. Remove EGR inlet and outlet pipes from intake and exhaust manifolds. Inspect manifold EGR ports, inlet pipes and outlet pipes for blockage/damage. If any problems are found, repair as necessary. After repairs, go to next step. If no problems are found, see DIAGNOSTIC AIDS .
  7. Turn ignition off. Reconnect all disconnected connectors. Turn ignition on. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate vehicle within conditions for running the DTC. See CONDITIONS FOR RUNNING DTC . If DTC runs and passes, go to next step. If DTC resets, go to step  2.
  8. Using scan tool, check for any other DTCs that are set. If no other DTCs are set, system is okay. If any other DTCs are set, repair DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
scientia non olet · About LEMON Manuals