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Ecu/TCU Checkout Procedure

  1. If during testing the Electronic Control Unit (ECU) or Transmission Control Unit (TCU) is found to be faulty, perform the following steps to ensure control unit is faulty. Most components are incorrectly diagnosed due to faulty electrical connectors or a poor mechanical connection between component and vehicle.
  2. Sometimes simply disconnecting and connecting an electrical component will provide a good electrical connection. Before replacing a control unit, check all components in the suspect circuit. If other components are okay, carefully disconnect control unit from vehicle harness.
  3. Inspect control unit harness connector and control unit contact pins for corrosion. Clean harness connector and control unit contact pins with contact cleaner. Inspect control unit harness connector for bent pins, missing pins and broken wires. Repair or replace as necessary.
  4. Connect control unit harness connector to control unit and retest system with DRB-II and adapter. If vehicle does not pass test and fails with the same message, replace control unit.
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