2001 Yukon XL ABS & Parking Brake Light after Rear Cargo Door Opened

[JGreene]

Hey all,
I started to get a "Cargo Light On" message and somehow (can't remember) realized that it probably had something to do with the GM after market security system that was installed. I removed the entire system and put everything back to stock. I also re-routed the ground located behind the engine manifold over to the better ground point on the firewall next to the hood lamp. A few weeks later, after we opened the rear cargo door (barn style), then the ABS and Parking Brake light came on while driving. I checked it all out and the brake system was OK. Now, we've found that those lights will come on from time to time after we've opened the rear doors. I've tried searching and looking for a similar post, but couldn't find anything. Does anyone have any insights or thoughts on what's going on and/or how to fix it?

P.S. This is for a 2500, if that makes any difference.

Thanks

 

[Doubeleive]

the car doors, rear hatch should be completely unrelated to the abs/brake light, but stranger things have happened, I would start with getting your hands on a obd scanner that will specifically do "ABS" and then when the lights are lit up scan it for the abs code and write it down.
the cheapy bottom of the barrel obd scanners will not read abs, the better ones up the ladder will usually do both ABS/SRS, be sure to check the label.
it is also worth noting that the abs code may not be stored when the abs light is not lit up, so scan it while the light is on.
your vehicle year has a known abs module issue where the solder inside the module cracks over the years and when you hit a bump in the road or perhaps even slamming a door shut can cause it to loose the connection and throw a code, then when you shut the key off and turn it back on the connection inside is good so module passes self test and the code is gone, until it looses connection again. the module is located under the vehicle pretty much right under the driver seat area, you won't be able to visibly see any issue with it but should it need to be repaired/replaced that's where it is located, it has 4 star bit screws, facing up from the module with barely any room to get to it, be careful if you need to remove it the bolts can strip easily and often they are full of dirt so getting a bit in there far enough to not strip it is tricky at best.

 

[JGreene]

Wow, great detailed advice. Thank you.

 

[68Chevysspu]

the car doors, rear hatch should be completely unrelated to the abs/brake light, but stranger things have happened, I would start with getting your hands on a obd scanner that will specifically do "ABS" and then when the lights are lit up scan it for the abs code and write it down.
the cheapy bottom of the barrel obd scanners will not read abs, the better ones up the ladder will usually do both ABS/SRS, be sure to check the label.
it is also worth noting that the abs code may not be stored when the abs light is not lit up, so scan it while the light is on.
your vehicle year has a known abs module issue where the solder inside the module cracks over the years and when you hit a bump in the road or perhaps even slamming a door shut can cause it to loose the connection and throw a code, then when you shut the key off and turn it back on the connection inside is good so module passes self test and the code is gone, until it looses connection again. the module is located under the vehicle pretty much right under the driver seat area, you won't be able to visibly see any issue with it but should it need to be repaired/replaced that's where it is located, it has 4 star bit screws, facing up from the module with barely any room to get to it, be careful if you need to remove it the bolts can strip easily and often they are full of dirt so getting a bit in there far enough to not strip it is tricky at best.

Thank you for that explanation. My 01 Suburban does the same thing except it’s when I hit a bump. I always figured it was a loose ABS sensor since it started after I replaced a front hub, and I suppose it might still be. This gives me another target though.

 

[MassHoe04]

I got the middle of the road Zurich scanner from Harbor Freight. It was about $150 (maybe $130 on sale), if I recall.

I bought my 04 Tahoe Z71 back in October. About two weeks with me, it started throwing ABS light and chimes anytime I got on the highway above 55 MPH.
It was only on the highway and at speed. Flashing and dinging at me off and on, until I got off the highway and slowed below 55.

I had fears that it was something like having to trace all the ABS wiring looking for shorts or maybe the bouncing ball of solder playing pinball inside the ABS controller circuit board.
I was afraid it would be expensive or difficult to figure out.

There were no stored codes, but the problem persisted.

I finally figured out how to get a little deeper into my Zurich scanner sub-menus. I found there was an area called something like "GM OEM Enhanced". Low and behold there was a code there that indicated an issue specifically with the left front ABS sensor. I waited until my pads and rotors came in, but I replaced that left front sensor and ABS was happy again.

Problem correctly identified by the scanner, problem solved! No lights/chimes and my ABS works as needed and when needed.

Long story short... My mid-level scanner was able to guide me to a specific issue within the ABS. It had features I wasn't even aware it had, until now...

While I hope to get a Tech 2 scanner someday, this unit from Harbor Freight really saved me a lot of time and money. You do get more out of higher-end scanners, but if you have a mid-grade unit, at least, you can do quite a bit of detective work on your own. You don't necessarily have to spend a fortune.

Good luck!

 

[Ella ramaley]

I had the same problem last summer with the ABS and Brake light coming on when when maybe hitting a bump or just driving for a while. When I turn the truck off and back on the lights aren't on. Eventually they return to on and then back off. I read about the replacing the brake module and the loose solder and the problem with accessing the screws to remove it. I let it go and the problem went away this winter, except for one warm day it was back. Mostly the lights have stayed off. I am wondering if the temperature has anything to do with this based on my experience. Also when lights are off , does that mean that the ABS is working? I haven't slammed on the brakes to test it. I am wondering if I need to get this fixed if the lights come back for safety reasons or is okay with old fashioned brakes. 2001 GMC Yukon SLE.

 

[Okiedave]

I had the same problem last summer with the ABS and Brake light coming on when when maybe hitting a bump or just driving for a while. When I turn the truck off and back on the lights aren't on. Eventually they return to on and then back off. I read about the replacing the brake module and the loose solder and the problem with accessing the screws to remove it. I let it go and the problem went away this winter, except for one warm day it was back. Mostly the lights have stayed off. I am wondering if the temperature has anything to do with this based on my experience. Also when lights are off , does that mean that the ABS is working? I haven't slammed on the brakes to test it. I am wondering if I need to get this fixed if the lights come back for safety reasons or is okay with old fashioned brakes. 2001 GMC Yukon SLE.

My 01 Yukon SLE has the same issue, for several years now. It is my understanding that the lights come on if it detects an issue, and they stay on, even if the issue corrects, until the next start up. So even a momentary change in the circuit triggers the lights, but the system still works. I have had the ABS used several times while the lights were on. I am starting to drive this truck more again, so I may need to revisit the issue. I just dont like having warning lights on.