What causes GM code 37?

Failed or misadjusted brake pedal switch Open wiring between the brake switch and ECM Blown brake light fuse cutting the signal feed Corroded connector at the brake switch

How do I fix GM code 37?

Confirm the brake lights work since they share the switch feed Check switch adjustment at the brake pedal Test for battery voltage in and out of the switch with the pedal pressed Inspect wiring to the ECM for opens Clear the code and verify TCC unlocks during braking on a road test

37 TCC Brake Switch Circuit Error

Q: What does GM code 37 mean?

GM code 37. TCC Brake Switch Circuit Error. Applies to 1988-1995 GM cars and trucks with automatic transmission and TCC.

Make: GM (1982-1995)
Category: Powertrain - Transmission
Severity: Check Engine Light
Applies to: 1988-1995 GM cars and trucks with automatic transmission and TCC

How to read it

Code 37 reads as 3 flashes, pause, 7 flashes on the check-engine light. Jump terminals A and B on the ALDL connector with the key off, then turn the key on with the engine off and count the check-engine flashes.

What does GM code 37 mean?

37. TCC Brake Switch Circuit Error. This code sets when your vehicle computer detects tcc brake switch circuit error.

Common causes of 37

Failed or misadjusted brake pedal switch
Open wiring between the brake switch and ECM
Blown brake light fuse cutting the signal feed
Corroded connector at the brake switch

How to fix 37

Confirm the brake lights work since they share the switch feed
Check switch adjustment at the brake pedal
Test for battery voltage in and out of the switch with the pedal pressed
Inspect wiring to the ECM for opens
Clear the code and verify TCC unlocks during braking on a road test