GM Electronic Parking Brake: Service mode

Understanding GM’s Electronic Parking Brake: How To Enter Service Mode

Most late-model GM vehicles include an  Electronic Parking Brake (EPB). The EPB offers a range of advantages over the traditional handbrake or foot-operated parking brake, but it also comes with some unique considerations. This article explores how to activate GM’s electronic parking brake service mode manually and then recalibrate the system once you’ve finished the brake job.

Entering Service Mode: Follow This Critical Procedure When Performing a Rear Brake Job On a GM Vehicle

GM vehicles are equipped with an electronic parking brake, which is different from the electronic parking brake systems used by other carmakers. The GM system uses a parking brake switch, usually on the console, a parking brake control module, and a cable. The parking brake control module contains a motor, an apply actuator, a release actuator, and a temperature sensor.

GM electronic parking brake control module with cable

How to activate the GM electronic parking brake service mode without a scan tool

Step-by-step procedure for putting the electronic parking brake into service mode manually.

1) Block the drive wheels.
2) Turn the ignition switch to the ON/RUN position with the engine off.
3) Place the automatic transmission in PARK or manual transmission in NEUTRAL, as equipped.
4) Apply and hold the brake pedal. The brake pedal must remain applied throughout the parking brake cable tension release process.
5) Press and hold down the electronic park brake (EPB) switch for approximately 5 seconds.
6) Observe the PARK BRAKE lamp on the instrument cluster.
7) When the PARK BRAKE lamp flashes, release, then immediately press and release the EPB switch. The parking brake cable tension is fully released.
8) Release the brake pedal.

How to exit the electronic parking brake service mode and recalibrate the system after you’ve completed the brake job.

Once you’ve completed the brake job, you must recalibrate the system and exit the electronic parking brake service mode. You can exit and recalibrate it manually or with a scan tool. Here’s the manual procedure.

1) With the ignition ON, apply and hold the brake pedal.
2) Push and hold the EPB switch down for 5-6 seconds.
3) Release the EPB switch.
4) Momentarily push the EPB switch down.
5) Remove the EPB MODULE fuse and reinstall.
6) Apply the EPB.
7) Release the EPB.

How the GM Electronic Parking Brake System Works

The parking brake control module receives the signal from the parking brake switch. The module first checks the internal circuit board temperature to make sure it’s within specs because the module also contains the motor. The electric parking brake can be activated when the vehicle is stopped or in motion.

To set the electronic parking brake, simply lift up on the parking brake switch. When activated, the module will flash the red park brake light momentarily flashes while the parking brake is being applied. Then the red park brake light stays on fully.

If the electric parking brake is applied while the vehicle is in motion, the driver will be notified by a chime sound and see a “Release Park Brake Switch” message. If the red park brake light is flashing, the electric parking brake is only partially applied or released, or there is a problem with the electric parking brake. The message “Service Park Brake” will be displayed. A flashing red electric parking brake light means the parking brake is being applied, is releasing or is only partially applied/released. If the system detects a fault, it will display a “Service Park Brake” message.

Release the GM electronic parking brake

To release the electric parking brake, the IGN switch must be in the ON or RUN position and the brake pedal must be fully applied. Then simply push down on the electronic parking brake switch. The red parking brake light will turn off.

©, 2021 Rick Muscoplat