Signal Circuit Inspection

Check for Open in Harness 

1. IG KEY: OFF, Engine: OFF
2. Disconnect ECM connector and TCM connector.
3. Measure resistance between terminal C17 of the ECM harness connector and A24 of the TCM harness connector.
4. Measure resistance between terminal C18 of the ECM harness connector and A16 of the TCM harness connector.
   1. Specification: approx. 0Ω
      Fig 1: Measuring Resistance Between Terminal C18 Of ECM Harness Connector And A16 Of TCM Harness Connector

      
5. Is the resistance near the specified value?

   YES

   1. Go to "Check for Short to Ground in Harness" procedure.

   NO

   1. Repair open in harness, Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

Check for Short to Ground in Harness 

1. IG KEY: OFF, Engine: OFF
2. Disconnect ECM connector and TCM connector.
3. Measure resistance between terminal C17 of the ECM harness connector and chassis ground.
4. Measure resistance between terminal C18 of the ECM harness connector and chassis ground.
   1. Specification: Infinite
      Fig 2: Measuring Resistance Between Terminal C18 Of ECM Harness Connector And Chassis Ground

      
5. Is the resistance near the specified value?

   YES

   1. Communication line is OK. Check the fault code related to TCM.
   2. Possibility of defective ECM. Temporarily test with a new ECM and check for proper operation.

      If problem is corrected, replace ECM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO

   1. Repair short to ground in harness, Go to "VERIFICATION OF VEHICLE REPAIR " procedure.