Skip the auto shop - Our mechanics make house calls

Q: Locked brakes - 2004 Cadillac CTS

asked by on

Gf said she was driving down the road and car all the sudden. Wouldn't go over 40 mph. Car smelled hot she pulled over. I checked the car out and the calipers were locked on front driver and rear passenger. I though by some freakind chance they went at same time and replaced them. When trying to bleed the calipers they locked again. I'm thinking it is the Ecbm but I'm not sure. Check engine light is on but abs is not. Can't take anywhere to get scanned and to have someone out to scan it will cost about 1/3 of the replacement ecbm. Any advice of what else could cause that issue or if a failing brake module can lock up opposite tires like that?

My car has 170000 miles.
My car has an automatic transmission.

A: Hi there. From the description you have pro...

Hi there. From the description you have provided, your vehicle’s left front and right rear caliper locking would have been a combination/proportioning valve before ABS (anti-lock brake system). The EBCM (electronic brake control module) controls the valves in the hydraulic modulator. It could be that the EBCM or hydraulic modulator is at fault.

It could also be stuck brake master cylinder check valve if the modulator is designed for diagonal braking. Braking systems used to be controlled front to rear. The engineers incorporated diagonal braking to balance the braking system. Your vehicle’s Check Engine Light being on should be addressed, although it is unlikely that it is related to the braking system. The ABS computer should be accessed to help determine the cause of the left front and right rear caliper locking-up.

I recommend having your vehicle’s locking brake calipers inspected and repaired by a certified technician, such as one from YourMechanic.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Keep having to add coolant

Hello. If you keep having to add coolant to the engine then it may be possible that there is a coolant leak, or that the engine may be consuming it somehow. I would carefully inspect the engine for any signs...

Q: 2004 Chevy Express makes noise while idling

The first thing you'd want to check is the power steering. A lot of times, they groan on those. If it's not the power steering, a lot of times it would be the transmission. If it's coming from the transmission,...

Q: The engine light came on

Hi, thanks for writing in. The hard start may happen after refueling due to a problem with the purge control valve leaking when it should be closed. If the code is for an emission leak detected then this valve that...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...