03 cclb that's been giving me fits with electrical issues. The first thing that happens is the brake light and abs light will come on and the ding ding ding. If I'm lucky it will end with that but I'm never lucky lol. That is followed by all kinds of lights coming on and off. Battery, airbag, security, will all come on and off along with the brake and abs. The gauges will stop working then start again and the dtc looks like it reboots or it will display service 4wd, or service brake system. Those will come and go. Horn stops working and sometimes if I have the outside air on it will switch it to inside air. I'm so lost with this I don't even know where to start. If I shut the truck off it will go back to being fine. Then after a bit it starts over. When I plug in my ppe tuner to get codes it shows none. But that's of course after I've shut the truck off. I'm not running any tunes currently, its stock. Any help is greatly appreciated.
LB7: Electrical gremlins and I have no idea where to start
- Thread starter pgr11
- Start date
Sounds like a ground issue to me, I would pull them all and clean them. They cause these trucks to do funky things
Please excuse my ignorance but approximately how many grounds do they have? Any particular ground to start looking at first or is it just random. In all honesty I'm lost with wiring issues.
Look under the truck at the body mount just forward of the drivers door. There is a ground bolt there with 2 or 3 wires hooked to it. It is a common problem for the ground to get dirty and lose contact. When it does the ABS goes dead, and it will short out the databus which will cause all the warning lights and loss of gauges. The ABS module is also known to fail and cause this. Overtime the potting on it can go bad, and road debris and crap gets into it, and shorts it out. Since it is tied into the data bus, it can take it down and cause all kinds of issues.
Great info. I'll check into that for sure. The first thing I noticed was the brake and abs light would randomly come on and ding just every so often but rarely. There was no other issues. Now all these other things are starting and its every time I drive. Thanks ago for pointing me in the right direction. I know I don't post much but I don't think I have much to add. I'm learning a great deal from you all.
I had a brake and ABS light that would light after hitting large bumps in the road. I later found that one of the wheel speed sensor wire attaching clips had broken and allowed the wire to rub on the inner sidewall of the tire. It finally wore in two and the light stayed on.
This is good source of information, page 55 in the second link gives the general location and type of ground.
http://gmupfitter.com/pdflists/view/6
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http://gmupfitter.com/files/media/photo/99/2006_LD_CKFullSizeElectrical.pdf
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Mine every so often throws the brake and ABS light, I was told it is because of the 35" tires and the ABS module not playing well together. but I figured you had more issues than just that
Is this the ground you referred too? It only has 2 wires but its in the right spot. It was loose so I took it off cleaned and prepped the area and tightened it all back up. I'll check to see if it worked after work.
Thanks guys. The ride home was nice and quiet. No ding, no lights, and no wacky gauges. Seems like the ground was the problem. If not I'll post back with more questions.
Yep, that's the one. GM has TSB's about this ground and problems with it causing all the issues you were having.
i agree, i had a similar issue due to the ground from the engine block to the fire wall being omitted by a mechanic. replacing the ground corrected the issue. there is also a ground in the base of the driver A pillar that is for several of the dash components including the cluster. the firewall ground is the primary ground for the dash and computers up front including the TCCM and BCM, IIRC from the all data diagram the pillar ground runs through the firewall ground to the block then the battery. the frame ground listed above is another good thing to check. cleaning grounds is free, just takes time with a wire brush or sand paper. make sure to paint , seal, or other wise coat over the freshly cleaned ground to prevent corrosion. the ground you posted is awfully cruddy, hopefully that fixed your issue, if not check the other two above.
Sorry to restart an old thread but I am having the exact same issue and can’t find anything about it except this. How did you fix this problem because it’s really bugging me now and I’m at a dead end
See links in post #7. Also, there are videos on Youtube about locating the ground point near the front dash speakers, well worth the time to watch a couple of them.