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 all connectors (and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage.

Has a problem been found?

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

IG Key "OFF".

Take off a connector of BSD switch.

IG "ON" or Engine "ON".

Measure a voltage between battery terminal and chassis ground about the steering BSD switch of connector.

Is the measured voltage within specifications?

	▶ Go to next procedure.
	▶ Check for open or short in the BSD switch circuit. ▶ Substitute with a known-good BSD ECU and check for proper operation. If the problem is corrected, replace BSD ECU and then go to "Verification of Vehicle Repair" procedure.

IG Key "OFF".

Disconnect BSD switch connector.

Measure resistance between terminal BSD switch harness connector and chassis ground.

Is the measured resistance within specification?

	▶ Go to next procedure.
	▶ Check for open or contact resistance in ground harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.