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 then go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Power Circuit Inspection" procedure.

IG "ON".

Measure voltage between motor power terminal of the HECU harness connector and chassis ground.

Is the measured value within specifications ?

	▶ Go to "Ground Circuit Inspection" procedure.
	▶ Check for open or blown fuse referring to "Circuit Diagram". ▶ Repair open or short in power circuit between battery and HECU harness connector and then, go to "Verification of vehicle Repair" procedure.

Ignition "OFF" & Engine "OFF".

Disconnect the HECU connector.

Measure resistance between ground terminal of the HECU harness connector and chassis ground.

Is the measured value within specifications ?

▶ Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "Verification of Vehicle Repair" procedure. note ※ In a case of replacing HECU, operate following functions 1) "Steering Angle Sensor Calibration" for steering angle sensor offset correction (refer to C1261) - ESP(ESC) only 2) "Longituginal Sensor Calibration" for Longituginal sensor offset correction (refer to C1285) - ESP(ESC) only

▶ Repair open or short in ground circuit between battery and HECU harness connector and then, go to "Verification of vehicle Repair" procedure.