How do you test for a bad ABS Control Module?
Thread Starter
|
Registered User
Joined: Feb 2022
Posts: 44
From: Syracuse,NY
Rep Power: 0
How do you test for a bad ABS Control Module?
I am getting no communicatIon from my brake control module. I have tested the canbus lines from the bank 2 module to the abs module and they are good. I get a brake warning light shortly after starting to drive. Any help with this would be appreciated. 2004 GTC.
Jason
Jason
Administrator
Joined: Jul 2014
Posts: 3,925
From: Montgomery NJ
Rep Power: 1002
Hello @V12diablo ,
Do you have a Ross-Tech scan ?
Have you inspected the connection pins at the ABS module, another member here had iirc, either brake fluid or other fluid around the pins, I had suggested an electrical spray cleaner, but he used brake kleen, please do not do that, as upon his plugging the abs module back in, it caught fire from the flammable brake kleen...
As to your brake warning in the dash, which warning is it, the yellow brake pad warning, the parking brake (Park), or brake failure warning ?
Edit: I would add that depending on the warning, I would check the brake light switch for any fault codes, be it intermittent or not, because, as seen in my rebuild thread at post #284 I had a brake warning accompanied by a EPC, TC, and ABS warnings, which all stemmed from a faulty brake light switch.
https://www.6speedonline.com/forums/...ctures-18.html
End Edit.
A picture and scan would help.
Johnny
Do you have a Ross-Tech scan ?
Have you inspected the connection pins at the ABS module, another member here had iirc, either brake fluid or other fluid around the pins, I had suggested an electrical spray cleaner, but he used brake kleen, please do not do that, as upon his plugging the abs module back in, it caught fire from the flammable brake kleen...
As to your brake warning in the dash, which warning is it, the yellow brake pad warning, the parking brake (Park), or brake failure warning ?
Edit: I would add that depending on the warning, I would check the brake light switch for any fault codes, be it intermittent or not, because, as seen in my rebuild thread at post #284 I had a brake warning accompanied by a EPC, TC, and ABS warnings, which all stemmed from a faulty brake light switch.
https://www.6speedonline.com/forums/...ctures-18.html
End Edit.
A picture and scan would help.
Johnny
Last edited by Johnny Hotspur GT; Jul 9, 2025 at 10:24 AM. Reason: Add information
Thread Starter
|
Registered User
Joined: Feb 2022
Posts: 44
From: Syracuse,NY
Rep Power: 0
Hi Johnny,
I did put all that info in this thread https://www.6speedonline.com/forums/...code-help.html but I got no response. In the mean time I will check the brake light switch. I did check all the connections and everything looks good and clean. I tested all my powers and grounds at the abs connector and all where good including power from the brake light switch pin 32, I was not able to test for power at cruise control brake switch pin 37 or esp switch pin 27. I do have VCDS and put the scans in the listed post.
Jason
I did put all that info in this thread https://www.6speedonline.com/forums/...code-help.html but I got no response. In the mean time I will check the brake light switch. I did check all the connections and everything looks good and clean. I tested all my powers and grounds at the abs connector and all where good including power from the brake light switch pin 32, I was not able to test for power at cruise control brake switch pin 37 or esp switch pin 27. I do have VCDS and put the scans in the listed post.
Jason
Last edited by V12diablo; Jul 11, 2025 at 05:33 PM.
Registered User
Joined: Feb 2018
Posts: 860
Rep Power: 53
Does the Emergency brake work?
Periodically mine displays the "P" warning. Then the scan comes back as no communication with the ABS controller. I haven't invested this condition further since it clears up the next drive cycle for some time. The E brake activators on my rears are not cracked either.
Periodically mine displays the "P" warning. Then the scan comes back as no communication with the ABS controller. I haven't invested this condition further since it clears up the next drive cycle for some time. The E brake activators on my rears are not cracked either.
Thread
Thread Starter
Forum
Replies
Last Post
Frank ( Sunnyside )
Bentley
20
Jan 20, 2026 09:07 AM