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Home >> GMC >> 1995 >> Forward Control 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 91 (Engine Controls - System/Component Tests - 5.9L Diesel) >> Computerized Engine Controls >> Powertrain Control Module (Pcm) >> Harness Check
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Harness Check

WARNING: This page is about a different car, the 1995 Dodge Pickup and 1995 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
  1. If PCM is found to be faulty during SELF-DIAGNOSTICS testing, perform following steps to confirm diagnosis. Most components are incorrectly diagnosed due to faulty electrical connectors or poor connections between component and vehicle. Sometimes simply disconnecting and connecting an electrical component will provide a good electrical connection.
  2. Before replacing a PCM, check all components in suspected circuit. If components are okay, carefully disconnect wiring harness connector from PCM.
  3. Inspect wiring harness connector and PCM terminal contact pins for corrosion. Clean wiring harness connector and PCM terminal contact pins with contact cleaner.
  4. Inspect PCM wiring harness connector for bent terminal contact pins, missing pins and broken wires. Repair or replace as necessary.
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