W/Harness Inspection

Engine Control
P0504 Brake Switch \'A\' / \'B\' Correlation - Inspection/Repair:_:W/Harness Inspection

Terminal and Connection Inspection

1. Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?






Power Circuit Inspection

Check for Open/Short on Power Circuit
1. Ignition "OFF".
2. Disconnect Stop Lamp Switch.
3. Measure voltage between Brake Light Switch terminal and chassis ground.
4. Measure voltage between Brake Test Switch terminal and chassis ground.
5. Ignition "ON".
6. Measure voltage between Brake Light Switch terminal and chassis ground.
7. Measure voltage between Brake Test Switch terminal and chassis ground.
Specification









8. Is voltage within the specifiation?






Signal Circuit Inspection

1. Ignition "OFF".
2. Disconnect Stop Lamp Switch and PCM harness connector.
3. Measure resistance between both ends of Brake Lamp Switch line.
Measure resistance between both ends of Brake Test Switch line.
4. Measure resistance between Brake Light Switch terminal of Switch harness connector and chassis ground.
Measure resistance between Brake Test Switch terminal of Switch harness connector and chassis ground.

Specification :Below 1Ohms (Only for No.3)
Infinite (Only for No.4)








5. Is resistance within specification?