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 "Power Circuit Inspection" procedure.

Ignition switch "OFF"

Refer to "Shop Manual" and disconnect the brake switch connector.

Ignition switch "ON"

Measure the voltage between Pin No. 1 (Power) terminal of brake switch harness connector and chassis ground.

Ignition switch "OFF"

Refer to "Shop Manual" and disconnect brake switch connector.

Ignition switch "ON"

Measure the voltage between Pin No. 3 (Brake Lamp Switch Power) terminal of brake switch harness connector and chassis ground.

Is the measured value within specification?

	▶ Go to "Signal Circuit Inspection" procedure.
	▶ Inspect and repair open or short in circuit, and then go to "Verification of Vehicle Repair" procedure.

Ignition switch "OFF"

Connect VMI to GDS and set up the Oscilloscope.(2 Channel):

Channel A (+) : Pin No. 1 (Power) terminal (Brake Switch Harness Connector)

Channel A (-) : Ground

Channel B (+) : Pin No. 3 (Brake Lamp Switch Power) terminal (Brake Switch Harness Connector)

Channel B (-) : Ground

Ignition switch "ON" & Engine "OFF"

Inspection condition : Ignition switch "ON" & Brake pedal operation

Is the measured value within specification?

	▶ Go to "Component Inspection" procedure.
	▶ Inspect and repair open or short in circuit, and then go to "Verification of Vehicle Repair" procedure.