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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 35 (Engine Controls - Tests W/Codes - 3.9L) >> Self-Diagnostic Tests >> Test TC-32A - EGR System Failure (DTC 32)

Test TC-32A - EGR System Failure (DTC 32)

WARNING: This page is about a different car, the 1995 Dodge Ram Wagon, 1995 Dodge Ram Van, 1995 Dodge Pickup, 1995 Dodge Dakota, and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS  section at the end of this article.
  1. Inspect condition and proper routing of all EGR system vacuum hoses. If EGR system vacuum hoses are okay, go to next step. If EGR system vacuum hoses are damaged or misrouted, repair as necessary. Perform TEST VER-2.
  2. Start engine. Allow engine to idle for at least 2 minutes. Disconnect Exhaust Gas Recirculation (EGR) solenoid electrical connector. Leave EGR solenoid electrical connector disconnected for remainder of test. Disconnect vacuum supply hose from EGR solenoid.
  3. Connect a vacuum gauge to end of disconnected hose. If vacuum gauge indicates less than 10 in. Hg, repair vacuum supply to EGR solenoid. Perform TEST VER-2.
  4. If vacuum gauge indicates more than 10 in. Hg, reconnect vacuum hose to EGR solenoid. Disconnect vacuum hose from EGR valve. Connect a vacuum gauge to end of disconnected hose. While observing vacuum gauge, momentarily raise engine speed to more than 2000 RPM.
  5. If vacuum gauge indicates less than 5 in. Hg while throttle is open, replace EGR valve assembly. Perform TEST VER-2. If vacuum gauge indicates more than 5 in. Hg while throttle is open, remove vacuum gauge.
  6. Connect a vacuum pump to EGR valve. With engine idling, slowly apply vacuum to EGR valve. If engine idle becomes rough as vacuum is applied, go to next step. If engine idle does not become rough, remove EGR valve and inspect manifold and EGR backpressure tube for restrictions. If restrictions are present, clean as necessary. Perform TEST VER-2. If no restrictions are present, replace EGR valve assembly. Perform TEST VER-2.
  7. Turn ignition off. Apply 10 in. Hg vacuum to EGR valve. Observe Vacuum gauge. If vacuum was not held for at least 10 seconds, replace EGR valve assembly. Perform TEST VER-2.
  8. If vacuum was held for at least 10 seconds, condition required to set trouble code is not present at this time. EGR SYSTEM FAILURE trouble code sets when Powertrain Control Module (PCM) performs a test of EGR system and does not see a significant change in oxygen sensor signal. Possible causes are: open or blocked vacuum supply to EGR valve, blocked exhaust transfer tubes to intake manifold, blocked backpressure tube to transducer, failed EGR valve, failed EGR solenoid/transducer or failed PCM. Go to next step.
  9. Inspect all related vacuum hoses and connectors. Repair as necessary. Perform TEST VER-2. If no problems are found with vacuum hoses and connectors, see INACTIVE TROUBLE CODE CONDITION . Perform TEST VER-2.
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