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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 26 (Engine Controls Self-Diagnostics - 5.0L & 5.7L) >> Diagnostic Tests >> DTC P0401: EGR System - Insufficient Flow >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2001 GMC Savana, 2001 Chevrolet RV Cutaway, 2001 Chevrolet Cutaway, and 2001 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing powertrain diagnostic system check, go to next step.
  2. If any MAP DTCs are set, repair those DTCs first. see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no MAP DTCs are set, go to next step.
  3. Observe FREEZE FRAME/FAILURE RECORDS data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate vehicle within code enable criteria or as close to FREEZE FRAME/FAILURE RECORDS data as possible. If DTC failed this ignition cycle, go to next step. If DTC did not fail this ignition cycle, see INTERMITTENT TROUBLE CODE DETERMINATION  under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.
  4. Inspect exhaust system for modification of original installed parts or leaks. If problem was found, repair as necessary. After repairs, go to step  8. If problem was not found, go to next step.
  5. Check EGR valve gasket and pipes for leaks. If problem was found, repair as necessary. After repairs, go to step  8. If problem was not found, go to next step.
  6. Remove EGR valve. See COMPONENT LOCATIONS . Visually and physically inspect EGR pintle and EGR valve passages. If problem was found, repair as necessary. After repairs, go to step  8. If problem was not found, go to next step.
  7. Remove EGR inlet and outlet pipes from exhaust manifold and intake manifold. Inspect manifold EGR ports and EGR inlet and outlet pipes for blockage caused by excessive deposits or other damage. If problem was found, repair as necessary. After repairs, go to step  8. If problem was not found, see DIAGNOSTIC AIDS .
  8. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate vehicle within code enable criteria. If DTC runs and passes, go to next step. If DTC does not run and pass, go to step  2.
  9. Using scan tool, observe stored information. If scan tool displays any DTCs that have not been diagnosed, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If scan tool does not display any DTCs, system is okay.
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