IG "OFF". Disconnect PCM/ECM connector.
IG "ON".
Measure voltage between Brake Light Switch terminal of PCM/ECM harness connector and chassis ground.
Measure voltage between Brake Test Switch terminal of PCM/ECM harness connector and chassis ground.
Step on the brake pedal.
Measure voltage between Brake Light Switch terminal of PCM/ECM harness connector and chassis ground.
Measure voltage between Brake Test Switch terminal of PCM/ECM harness connector and chassis ground.
Test Condition | Brake Test Switch | Brake Light Switch |
Step on brake pedal | Battery Voltage | Battery Voltage |
Release brake pedal | Approx. 0V | Approx. 0V |
Is voltage within specification?
 | ▶ Check for poor connection between PCM/ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure |
 | ▶ Check Stop Lamp Switch for contamination, deterioration, or damage. Substitute with a known-good switch and check for proper operation. If the problem is corrected, replace switch and then go to "Verification of Vehicle Repair" procedure. |
