Technical Definition:

Brake Switch A / B Correlation

Technical Description:

Possible Causes:

• The most common is the brake light switch whose failure is due to wear.
• The brake light fuse will fail at times due to moisture in the circuit or burning out the brake light.
• Brake light bulb failure is another cause many times due to water infiltrating into the lens.
• The wiring harness, more specifically the connectors are loose or pushed out pins will cause a correlation problem between the switch and PCM.
• Lastly, the PCM itself could have failed.

Possible Symptoms:

• The brake lights will either be illuminated continuously or fail to illuminate as the pedal is depressed
• It will be difficult or impossible to shift out of park
• The vehicle may stall when the brakes are depressed while a cruising speeds
• The cruise control will not activate

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

Specific Makes: