Disconnect the Stop Lamp Switch and PCM connectors and inspect for looseness, poor connection, bending, corrosion, contamination, deterioration or damage. Reconnect the connectors.

Connect the GDS and go to ""Current Data"".

Monitor Stop Lamp Switch values in Current Data, check and wiggle the harness(es), connector(s), and terminal(s).

Any change in the values indicates a poor connection. Was a connector problem found?

	▶ Repair the connector. Go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Power Circuit Inspection" procedure.

IG "OFF". Disconnect PCM connector.

IG "ON". Release Brake Pedal. (Measurement "A").

Measure the voltage between brake switch signal terminal of PCM harness connector and chassis ground.

Measure the voltage between brake lamp signal terminal of PCM harness connector and chassis ground .

Apply the brake .(Measurement "B")

Measure the voltage between brake switch signal terminal of PCM harness connector and chassis ground.

Measure the voltage between brake lamp signal terminal of PCM harness connector and chassis ground .

Is the measured voltage within specification ?

	▶ Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Check open in harness" as follows.

IG "OFF". Disconnect stop lamp switch connector.

Measure the resistance between brake switch signal terminal of PCM harness connector and brake switch signal terminal of Stop lamp switch harness connector.

Measure the resistance between brake lamp signal terminal of PCM harness connector and brake lamp signal terminal of Stop lamp switch harness connector.

Is the measured resistance within specification ?

	▶ Go to "Check Battery voltage" procedure.
	▶ Repair open in circuit. Go to "Verification of Vehicle Repair" procedure.

IG "OFF". Disconnect stop lamp switch connector.

Measure the voltage between power supply terminals of stop lamp switch harness connector and chassis ground.

IG "ON"

Measure the voltage between power supply terminals of stop lamp switch harness connector and chassis ground.

Is the measured voltage within specification ?

	▶ Substitute with a known - good stop lamp switch and check for proper operation. If the problem is corrected, replace stop lamp switch and go to "Verification of Vehicle Repair" procedure.
	▶ Check the fuse between battery and stop lamp switch. ▶ Repair open or short in power circuit of stop lamp switch. Go to "Verification of Vehicle Repair" procedure.