Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found?

	▶ Repair as necessary and go to "Verification of vehicle Repair" procedure.
	▶ Go to "CAN communication circuit inspection" procedure.

IG "OFF"

Disconnect ECM/PCM harness connector.

Measure resistance between High signal terminal and Low signal terminal of ECM/PCM harness connector.

Is resistance within the specification?

	▶ Go to next step as below.
	▶ Check for open in wiring related to the CAN communication(ECM/PCM, EPS, MTS and vertical resistor at the junction box). Repair as necessary and then go to "Verification of Vehicle Repair" procedure. note Vertical Resistor Resistance : Approx. 110~130Ω

Measure resistance between High signal terminal of ECM/PCM harness connector and chassis ground.

Measure resistance between Low signal terminal of ECM/PCM harness connector and chassis ground.

Is resistance within the specification?

	▶ Go to next step as below.
	▶ Repair CAN communication line for a short to ground. And then go to "Verification of Vehicle Repair" procedure.

Disconnect the connectors related to the CAN communication.

Ignition "ON" & Engine "OFF".

Measure voltage between High signal terminal of ECM/PCM harness connector and chassis ground.

Measure voltage between Low signal terminal of ECM/PCM harness connector and chassis ground.

Is voltage within the specification?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
	▶ Go to next step as below.