Brake light and ABS come on intermittently

[Wires]

The lights both come on at the same time, and it happens about once every 2-4 weeks. Once I shut the engine off and turn it back on, they're gone. Things I know:

 

- Brake fluid is at the proper level

- The brake pedal has always been very spongy and crappy feeling

- ABS kicks in when it shouldn't (any little bump while braking)

 

 

Is there any common fail points in the brake system that could cause these issues? Like a sensor or a module? I figured I'd ask here before paying a dealership to diagnose it.

 

 

 

 

 

On the GMT-800's, the ABS / brakes aren't very good. Drive over a pothole, and the ABS kicks in, it's just a fact of life. If you take your foot off the brake and brake again, it will release the ABS and brake normally.

 

The petal is typically spongy, and it feels like you need to stand on it to stop.

 

As with the ABS, like mentioned above, it's probably a bad module. If it was like my '00 Z71, there was no way to get that rusted thing off the frame rail. I decided to just accept it was screwed, ignore the ABS light.

 

Braking was always better (for me), since as mentioned above, ABS sucks on these trucks.

[99gst_racer]

Over a decade ago, I drove my girlfriend's mom's '01 Yukon XL to my highschool prom. I remember her brakes being very touchy and responsive. I know the truck was practically brand new back then, but it at least shows that at some point, the brakes on these models did feel proper. So, what happens to allow the brakes to eventually feel like mush? I would gladly replace a part or two in the hydraulic system (if that's what it takes) to have tight and responsive brakes like her way back when.

[absinthminded]

What up Pdogg? My truck started to do the same thing under low speed breaking. Guess I will start with cleaning the sensors and checking the grounds. Then I will have the codes scanned.

[KK2000]

Have a 2000-Silverado 1500, same problems. ABS & Brake light on intermittently. Could not get any codes to read when lights were on (engine on also at same time) with a very good Craftsman scanner (Not sure if it can read all codes as of yet- borrowed scanner) BUT. When I went to check the ground on the frame, it was loose/stripped. Just a tapped hole in the frame. Cleaned it all up and used nut & star washer to keep it all tight. Just info at this point. Let you know after a bit

[mxeightyeight]

TECHNICAL

Bulletin No.: 04-05-25-002E

Date: March 11, 2009

Subject:
ABS Light On, DTCs C0265, C0201, U1041 Set and/or Loss of Communication with Brake Module (Reground EBCM Ground)

 

Models

Supercede:

This bulletin is being revised to add step 2 to the procedure and update the Parts and Warranty Information. Please discard Corporate Bulletin Number 04-05-25-002D (Section 05 - Brakes).

Condition

Some customers may comment that the ABS light is on. Upon further inspection, DTCs C0265 and C0201 may be set in the brake module. It is also possible for DTC U1041 to set in other modules. There may also be a loss of communication with the brake module.

Cause

A poor connection at the EBCM ground is causing unnecessary replacement of brake modules.

Important:
The EBCM ground is different for each application. Refer to the list below for the proper ground reference:

 

Correction

Important:
Do not replace the brake module to correct this condition. Perform the following repair before further diagnosis of the EBCM.

 

Perform the following steps to improve the connection of the EBCM Ground:

1. Remove the EBCM Ground. The EBCM Ground is located on the frame beneath the driver's side door. If multiple grounds are found in this location, the EBCM ground can be identified as the heavy (12-gauge) wire.

2. If the original fastener has a welded on nut, remove the nut from the frame, and if required, enlarge the bolt hole to accommodate the new bolt and nut.

3. Clean the area, front and back, using a tool such as a *3M Scotch-Brite Roloc disc or equivalent.

4. Install the ground, then the washer and then the bolt to the frame.

Important:
It is important to use the bolts, washers and nuts specified in this bulletin. These parts have been identified due to their conductive finish.

 

5. Install a washer and nut to the back side of the frame.

Tighten

Tighten the nut to 9 Nm (79 lb in).

6. Cover the front and back side of the repair area using Rubberized Undercoating.

An additional check can be made to ensure a good connection for the battery cable to frame ground. It is possible for this ground to cause similar symptoms with the ABS as described above.

*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources.

 

 

Another thing to try is unplug the connector from the module (driver side, frame rail) and check for corrosion on the connector. (This was the problem with mine which would through both lights for less than a second and would turn off) If you find corrosion, hit it with your favorite contact cleaner and clean the connectors, then spray with something like WD-40. I suppose you could use dielectric grease now that I think about it.