Many malfunctions in electrical systems 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.

Monitoring a DVOM on min/max or the VMI while wiggling connectors may help find the problem.

Has a problem been found?

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

Ignition "OFF".

Disconnect Stop Lamp Switch harness connector.

Ignition "ON".

Measure Voltage between Power terminal of Stop Lamp Switch harness connector and chassis ground .

Is the measured Voltage within specifications?

	▶ Go to Next procedure.
	▶ Check for open and short to ground in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

Ignition "OFF".

Disconnect Stop Lamp Switch and Stop Lamp Relay and EPB ECU main harness connector.

Measure resistance between Signal terminal of EPB ECU harness connector and chassis ground.

Is the measured resistance within specifications?

	▶ Go to Next procedure.
	▶ Check for short to ground in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

Ignition "OFF"

Disconnect Stop Lamp Switch and Stop Lamp Relay and EPB ECU main harness connector.

Measure resistance between NO terminal of Stop Lamp Switch harness connector and NO terminal of EPB ECU harness connector.

Measure resistance between NC terminal of Stop Lamp Switch harness connector and NC terminal of EPB ECU harness connector.

Is the measured resistance within specifications?

	▶ Go to Next procedure.
	▶ Check for open in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.