Help Diagnosing ABS Problem (ECB, ABS, VSC lights)

I need help diagnosing the brake problem on my daughter's 2004 model. I've read through quite a few chat threads, but wanted to run the situation by the experts here before investing in a replacement ABS accumulator (and the tools/equipment/software too)! Below are the details of the situation and what I've done so far.

Last week my daughter called and told me that all her brake warning lights came on when she was leaving for school and the bakes felt like they required more pressure to stop. When I arrived, I verified the lights were on (Brake, ECB, ABS and VSC). I also verified that the brakes felt week, almost like only the rear brakes were engaging. I also verified that the e-brake was disengaged.

Based on this forum, the first action I tool was to use a jumper wire and pull the brake codes. This is what I retrieved:
ECB - 41 and 68
ABS - 42
VSC - 45

The next step was to disconnect the 12v battery and clean the terminals, leaving the battery disconnected for several minutes. The ground terminal had a little light corrosion, but not bad. I didn't have my multimeter along, so I didn't test the battery voltage. However, I replaced the battery sig months ago, so it should be fine. After that, I checked the brake fluid reservoir. The fluid was at the "add" mark, but not below it, so I topped it up. I even went as far as loosening and retightening the gas cap a couple times. When I rechecked the codes, the ECB 41 code disappeared, but the other three codes remained. Next, I tried clearing the codes using the jumper wire and quickly pressing the brake multiple times (thanks again to this forum), but the three codes remained. I did it multiple times to verify it was done correctly.

Based on the codes and what I've shared, does anyone have advise on additional tests or checks I can do before investing the time, effort and money in replacing the ABS accumulator? My daughter was forced to borrow our Suburban and driving it is killing her!

 

That's interesting. If it was due to the brake fluid level, topping it up should have fixed the code. Hmmm...

 

Does anyone else have any thoughts or guidance?

 

Thanks for the response. For some reason I only received email notifications for the first response from @dolj and your last response. I didn't get a notification of your first response or the response from mr_guy_mann or the last response from @dolj. Not sure why.

Now that I see them, I'm going to take a closer look at the brake fluid reservoir. I just had to drop the money on the ABS accumulator and related tools/supplies/software/etc and have it turn out to be something else.

Thanks again!

 

Good to know!

 

Thanks... I'll keep digging!