ABS Light

I posted the trouble tree for the code's C0251,C0246,C0242,C0252,and C0245.Code C0265 is a code for a internal failure in the ebtcm also. So your best bet is to follow the trouble tree i posted. Here is the description for the code's.
DTC C0241-C0254 or C041-C054

This video will show you how to scan the ABS system.

https://youtu.be/rTtAnsOlZU4

and

https://www.2carpros.com/articles/abs-warning-light-on-easy-repair-guide

Circuit description:
The ABS relay supplies battery voltage to six valve solenoids (right front dump/isolation, left front dump/isolation, and rear dump/isolation). The EBCM microprocessor applies the grounds needed to activate each solenoid. The low side of each solenoid coil has a feedback circuit to the EBCM microprocessor. When a solenoid is commanded off the feedback voltage is high. When a solenoid is commanded on, the feedback voltage is low.

Conditions for Running the DTC

* The ignition is on.
* The vehicle speed is greater than 6 km/h (4 mph) .

Conditions for Setting the DTC
The EBCM detects an internal malfunction.

Action Taken When the DTC Sets
C0241, C0242, C0245, C0246, C0251, C0252, C0253, C0254
If equipped, the following actions occur:

* The EBCM disables the DRP/ABS.
* The ABS indicator turns on.
* The red Brake warning indicator turns on.

C0243, C0244, C0247, C0248
If equipped, the following actions occur:

* The EBCM disables the ABS.
* The ABS indicator turns on.

Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids
An intermittent open/shorted solenoid DTC can be set by several different internal EBCM problems. Replace the EBCM if an open/shorted solenoid DTC continues to set intermittently.

This is a common problem with the ABS control module we replace them all the time.

Here is a guide and a video on how the job is done.

https://www.2carpros.com/articles/how-to-replace-a-abs-controller

and

https://youtu.be/lUotkKXG9dY

You can find one on Amazon for 615.00 Delco unit

https://www.amazon.com/gp/product/B01E6GA9OU/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=2carprcom-20&creative=9325&linkCode=as2&creativeASIN=B01E6GA9OU&linkId=6778b295cb1d5efa7a28202914a62b6a

Please let us know what happens.

Cheers, Ken

Depends on the codes it is throwing, but the GM ABS units have problems with the power relays and the such and they are built into the EBCU. The odds of it being the computer ar pretty good

There are more than just wheel sensor issues with that system. You need to have the ABS system scanned for codes to know why the lights are on. It has disabled the ABS for now, so yes you have brakes, but no ABS. With a failure code we can see exactly why the light is on

If the brake fluid is full, chances are you have either a bad sensor or wiring issue at the sensor. Have you ever had the computer scanned when the ABS light is on?

It could be something as simple as low brake fluid. However, the scanner should direct you to the correct component that is causing the light.

Check it out and let me know what you find.

Joe

TEST A: ABS INDICATOR ALWAYS ON
Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK under DIAGNOSIS & TESTING. After performing diagnostic system check, go to next step.
Turn ignition off for 5 seconds. Turn ignition on and observe ABS indicator light. If indicator light illuminates for 2 seconds then turn off, problem is intermittent. If indicator light does not illuminate for 2 seconds or does not turn off, go to next step.
Using scan tool, select instrument panel cluster special functions menu. Command ABS indicator light off. If indicator light turns off when commanded, go to step 5. If indicator light does not turn off when commanded, go to next step.
Replace instrument panel cluster. After replacing instrument panel cluster, go to step 6.
Replace EBCM. After replacing EBCM, go to next step.
Turn ignition off for 5 seconds. Turn ignition on and observe ABS indicator light. If indicator light illuminates for 2 seconds then turn off, system is okay. If indicator does not illuminate for 2 seconds or illuminates but does not turn off, go to step 3.

You need to check the trouble codes for the abs first. Let me know what the codes are.

ABS system :*** have it scanned for codes ***

only way you can find out why the light is coming
very common is brake light switch or front wheel bearing and sensor
need to have the codes

Let me know what you have for codes
(when you do )