REAL MAN TRUCKWORKS & SURVIVAL
VEHICLES, CAMPERS, and BOATS => General Maintenance, How to/DIY projects => Topic started by: Sammconn on October 28, 2014, 10:13:38 PM
-
Hi guys. I have a 2006 LBZ with about 180k on the clock. A while back my ABS and brake light came on together, and have remained up together since. I commenced a normal mans oil change and inspection, front diff, trans, transfer case and had normal used oil come out. Had a bad wheel bearing and changed it too. All seems to be normal from my point of view. My scan tool can get to the ABS stuff, but that's about it.
Here's what I found when I hooked it up:
In park 3 MPH on all sensors.
While driving all three respond normally.
So, I did some research and it appears that my ABS module may need an update or reboot.
Does this sound right? I'm at a loss and don't just want to go throwing money at parts I don't need, and my truck hasn't seen a dealer in about 150k. I don't have access to a tech2 as I'm way out in the sticks 750 odd miles from a dealer I would trust.
Is there a way to reboot the module without a tech2?
Thanks. Sam
-
Never heard of a "reboot" on the module, but those modules go bad all of the time. The main power relay is soldered to the board inside the module when every other relay on the truck is replaceable.
Also, A bad connection at the battery(s) can cause the same issue, or even a bad battery. If voltage drops to much while cranking (below 9.5ish), the module won't wake up properly. This or a bad relay will have the same codes usually.
-
I'll have to look at the battery connections. I had one get oxidized this summer, maybe...could it really be this easy.
If this isn't it, where exactly is the module located. I have the tools to maybe change the relay if that is a possibility. I do some electronics repairs as a part of my job.
Thanks Ken.
-
No problem.
The module is on top of the abs unit, on the frame below driver's seat.
-
Never heard of a "reboot" on the module, but those modules go bad all of the time. The main power relay is soldered to the board inside the module when every other relay on the truck is replaceable.
Also, A bad connection at the battery(s) can cause the same issue, or even a bad battery. If voltage drops to much while cranking (below 9.5ish), the module won't wake up properly. This or a bad relay will have the same codes usually.
Ken's the guru on this stuff. I can say however that bad ground issues have caused more problems with more vehicles than I can count, and usually are ignored in favor of pricier and more complicated diagnosis. whenever I have electrical issues nowadays, the first thing I do is clean the terminals, pull the battery, and chase the ground wire back to the chassis and get out the wire brush. after doing a much better job getting to bare metal than any manufacturer, checking the wire for corrosion under the sheathing, I coat it in anti-corrosion battery grease, and hook it all back up. I would say 75% of my problems are typically solved following this method.
-
Good advice Tate, especially in wet or humid environments. Out here, bad grounds happen, but not often. If so, it's usually human caused.
-
Never heard of a "reboot" on the module, but those modules go bad all of the time. The main power relay is soldered to the board inside the module when every other relay on the truck is replaceable.
Also, A bad connection at the battery(s) can cause the same issue, or even a bad battery. If voltage drops to much while cranking (below 9.5ish), the module won't wake up properly. This or a bad relay will have the same codes usually.
Ken's the guru on this stuff. I can say however that bad ground issues have caused more problems with more vehicles than I can count, and usually are ignored in favor of pricier and more complicated diagnosis. whenever I have electrical issues nowadays, the first thing I do is clean the terminals, pull the battery, and chase the ground wire back to the chassis and get out the wire brush. after doing a much better job getting to bare metal than any manufacturer, checking the wire for corrosion under the sheathing, I coat it in anti-corrosion battery grease, and hook it all back up. I would say 75% of my problems are typically solved following this method.
You are spot on. On the outside of the frame rail just about where your driver's feet are is a set of grounds that are very commonly corroded on these trucks. Give that a shot.
-
Yeah, I've already checked out that ground, it was good. We've got all kinds of blizzard going on now, so I now need to get the truck indoors and thawed out.
It sees more than a lot of gravel, 200 miles one way to get out of here, and done it a lot, so now that I know where it is, it may just be a broken wire.
Hoping to get a look at it over the weekend, and yes I'm aware it's already here. :-\
Thanks for the ideas guys, I'll keep you posted on what I find.
(and where is the popcorn guy?)