After replacing the brakes, the wheels lock up and codes C1232 and P0318

KINGDAVID3533

MEMBER
2003 CADILLAC CTS
3.2L
V6
2WD
AUTOMATIC
120,000 MILES

After replacing the brakes on all four wheels. Test drove the vehicle and felt and bumping or thud coming from the car. After getting back home and letting the car sit the passenger rear and driver's front brakes were locked up. I went ahead and drove the car again anyway and noticed that the calipers were getting super hot on those wheels. I'm also getting DTC codes C1232 and P0318. I tested the wheel sensors, and they are good. Why are my wheels locking up?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Hi,

This is an interesting one. It appears to be related to the ABS/Traction control system. However, it can be caused by a wheel speed sensor. Not here is the interesting part. There is nothing that would apply brake pressure to two of the wheels when you release the pedal unless the module believes there is wheel spin. Take a look at the two definitions below.

P0318 is related to a communication issue with the EBCM (electronic brake control module).

C1232 See pic 1 below.

Were the wheels locked up after the vehicle was turned off and cooled off? Also, how were the wheel speed sensors checked?

I need you to try something. Lift one of the wheels with a locked brake. Open the bleeder valve on the caliper. The wheel should spin. Have a helper (key off) apply the brakes so it locks. Then, have the helper release the brake and see if the caliper is still locked.

Additionally, please check all connectors and wiring to the sensors, and let me know if you have a live data scan tool. If you do, check wheel speed sensor output and confirm if they are the same at each wheel.

Let me know what you find or if you have questions.

Take care,

Joe

PS: I forgot to ask. Was the hydraulic system opened for any reason?

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