2012-2013 Buick Regal Parking Brake Problems and Adjustment

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2012-2013 Buick Regal does not have a parking brake pedal or a cable you adjust by hand. It uses an Electric Parking Brake (EPB) run from a switch on the center console, and the brakes adjust themselves for wear every time they are applied. When the parking brake acts up on this car, the fix is usually diagnosis and calibration, not a cable adjustment, and the dash lights tell you most of what you need to know.

How the Regal's Electric Parking Brake Works

GM's owner manual for the 2012 Regal describes the system plainly: the vehicle has an Electric Parking Brake, the switch is on the center console, and the EPB can be activated even with the ignition off. A control module with its own internal motor, apply actuator, release actuator and temperature sensor does the work that a hand lever and cable used to do.

• To apply: with the car stopped, lift up on the EPB switch momentarily. The parking brake status light flashes while the brake is applying and stays on once it is fully applied.
• To release: put the ignition in ON/RUN, press and hold the brake pedal, and push down on the switch. If you try to release it without your foot on the brake, a chime sounds and the Driver Information Center (DIC) shows a message.
• Automatic release: with the engine running and the car in gear, the EPB releases on its own when you drive away. GM advises avoiding hard acceleration against an applied EPB to preserve parking brake lining life.
• Parking on a hill: the manual says to pull the switch twice for maximum EPB force.
• In motion: holding the switch up while moving slows the car for as long as the switch is held, with a chime and a DIC message. Letting go of the switch releases the brake.

Two points catch owners out. First, the EPB needs electrical power: GM states that with insufficient electrical power the EPB cannot be applied or released. A weak or dead battery can leave the car stuck with the brake on, or unable to set it. Second, repeatedly cycling the EPB with the engine off drains the battery, so do not play with the switch while parked with the engine off.

Warning Lights and DIC Messages: What Each One Means

The Regal has two separate parking brake lights plus three parking-brake-related DIC messages. Reading them correctly is the first step in any diagnosis.

The warning light should also come on briefly when the ignition is placed in ON/RUN as a bulb check. If it never lights at all, the manual says to have the car serviced.

Common Regal Parking Brake Problems and How to Diagnose Them

Brake will not release or will not apply

Start with the battery and charging system. Because the EPB is electrically operated, low system voltage is the simplest reason it will not move. Confirm you are following the release sequence exactly (ignition ON, foot on the brake, switch down). If the brake still will not release, do not drive on it. GM warns that driving with the parking brake on can overheat the brake system and cause premature wear or damage to brake parts.

Status light keeps flashing

A continuously flashing status light means the system thinks the brake is only partly applied or released, or it has a fault. GM's instruction is to release and re-apply. If it keeps flashing, the car should not be driven until the EPB is checked. If the EPB will not apply at all while parked, the manual says to block the rear wheels so the car cannot roll.

Parking brake warning light on with slow apply and release

This light points to an error in another system, not necessarily the parking brake itself. The EPB still works in a reduced mode if you hold the switch. Reading stored codes from the brake and body control modules is the right next step rather than replacing parts on a guess.

Car creeps on a hill with the EPB set

That is a holding-force problem. Worn, glazed or contaminated rear pads, or a rear rotor surface in poor condition, all reduce what the parking brake can hold. Try the double pull on the switch first, then inspect the rear brakes.

Parking Brake Adjustment and Calibration

There is no owner cable adjustment on this system. The manual's Brake Adjustment note says that every time the brakes are applied, with or without the vehicle moving, the brakes adjust for wear. What the EPB can need after certain repairs, such as rear brake work or a module replacement, is a calibration so the module relearns its apply and release positions.

According to Brake & Front End magazine, the Regal's EPB module can be calibrated with or without a scan tool. The no-scan-tool sequence they publish is:

1. Turn the ignition ON and press and hold the brake pedal.
2. Push and hold the EPB switch down for 5 to 6 seconds.
3. Release the switch.
4. Push the switch down momentarily.
5. Remove the EPB MODULE fuse and reinstall it.
6. Apply the electric parking brake.
7. Release the electric parking brake.

Once calibrated, test holding ability with GM's own check: park facing downhill on a fairly steep grade with room in front of the car, keep your foot on the service brake, and set the parking brake. With the engine running and the transmission in Neutral, slowly ease off the brake pedal until only the parking brake is holding. Be ready to press the service brake immediately if the car starts to move.

Rear Brake Service on an EPB Regal: What to Replace Together

Because the parking brake holds the car through the rear brakes, most parking brake complaints that are not electrical end up as a rear brake job. A few things matter on this car:

• Replace pads as axle sets. GM's manual says brake linings should always be replaced as complete axle sets. Do both rear wheels together and inspect the rear rotors at the same time.
• Do not force the rear piston back blind. Check the factory service information for how the rear piston retracts on this EPB system before you push on it, and run the EPB calibration afterward so the parking brake sets correctly on the new pads.
• Use new caliper bracket bolts. Brake & Front End reports that the Regal uses torque-to-yield bracket bolts: rear bolts are tightened to 100 Nm (74 lb-ft) plus a 60-degree turn, and fronts to 150 Nm (111 lb-ft) plus 45 degrees and then another 15 degrees. These bolts stretch permanently, so replace them rather than reuse them, and use a torque angle gauge.
• Hardware and fluid. Fresh brake hardware kits keep pads sliding freely, which matters for both service braking and parking brake holding. The reservoir takes DOT 3 or DOT 4 as marked on the cap. If yours is DOT 4, GM recommends flushing and refilling the brake/clutch hydraulic system every two years.

Shop brake pads and brake rotors for the rear axle, and see brake calipers if a caliper is seized or leaking.

While the car is up, look at the fronts too. Base Regals use single-piston front calipers while the GS uses twin-piston calipers, so confirm which system your car has before ordering. For 2012-2013 Regals we carry the Brembo OE front disc brake kit with UV-coated rotors and ceramic pads and, for 2012 Regals with Brembo calipers, the Hawk Talon drilled and slotted front rotor set.

One more thing worth checking with the rear wheels off: NHTSA lists recalls for 2012-2013 Regals registered in salt-belt states covering rear suspension toe links that can corrode and fracture. Check your VIN for open recalls; dealers replace the toe links free of charge.

How Hard Is the Job?

Diagnosing the EPB from the lights and DIC messages, and running the published calibration sequence, is within reach of any owner. A rear pad and rotor job is a moderate DIY task on this car, made harder than on an older car by two things: the EPB has to be handled correctly during piston retraction and calibrated afterward, and the torque-to-yield bracket bolts need new bolts and a torque angle gauge. If the problem is a module fault, an error in another system, or a status light that keeps flashing after calibration, a shop with a GM-capable scan tool is the faster route.

Frequently Asked Questions

Can I adjust the parking brake cable on a 2012 Buick Regal?

No owner adjustment is called for. The Regal uses an Electric Parking Brake, and GM's manual says the brakes adjust for wear every time they are applied. If holding force is poor, inspect the rear brakes and recalibrate the EPB rather than looking for a cable adjuster.

Why will my Regal's parking brake not release?

Check that the ignition is ON and your foot is firmly on the brake pedal before pushing the switch down. If the battery is weak, the EPB may not have enough power to release. A SERVICE PARKING BRAKE message or a flashing status light points to a system fault that needs diagnosis.

Is it safe to drive with the parking brake light flashing?

No. GM's manual says not to drive the vehicle if the parking brake status light keeps flashing after you release and re-apply the brake. It means the brake may be partly applied or the system has a fault.

Do I need a scan tool to replace rear pads on a Regal with an electric parking brake?

Brake & Front End reports the Regal's EPB module can be calibrated with or without a scan tool, and publishes a switch-and-fuse sequence for doing it without one. Check the factory service information for the correct rear piston retraction method before starting.

What brake fluid does a 2012-2013 Regal use?

DOT 3 or DOT 4, as marked on the reservoir cap. Use only the type shown, from a new sealed container. For DOT 4 systems, GM recommends a flush and refill every two years.

Should I replace front and rear brakes at the same time?

Not necessarily. Replace pads as complete axle sets, front or rear, when each axle needs it. It is a good time to inspect both axles and the rear suspension while the car is in the air.

Sources

1. 2012 Buick Regal Owner Manual (GM) - EPB operation, status and warning lights, DIC messages, battery note, parking brake check, brake adjustment, axle sets, DOT 3/DOT 4 fluid and two-year flush
2. Brake & Front End: Brake Service On 2011-Newer Buick Regals - EPB module components, calibration with or without a scan tool, seven-step calibration, single vs twin-piston fronts, torque-to-yield bolts
3. Brake & Front End: Buick Regal (2011-2016) Brake Pad and Rotor Replacement - rear caliper bracket bolt torque and angle
4. NHTSA recall data, 2012 Buick Regal - rear toe link corrosion recalls (20V764, 21V633, 21V00F, 26V113)