2001 Tahoe LS PROBLEMS help?

[ribs2k]

I thought my Tahoe may have been struck by lightening. We had a very bad storm here in Colorado Springs and the next morning I had a bunch of issues appear suddenly. First off my dash lit up with the ABS light, service engine soon light and than my message center said service 4 wheel drive. So first off I started it up and shifted into drive and the automatic transmission stayed in the highest gear. It would randomly shift into different gears on its own. My solution was to manually shift. This led to my high gear slipping. Next I tried my 4 wheel drive and it did not work at all. My ABS isn’t working right either.
So I took it to the shop and this is what they have done so far. First they replaced the transmission,(they said it might just fix my shifting issues as well). Nothing changed other than my high gear isn’t slipping,(but now I have to push the shifter down several times before I can get it into first gear). Next they replaced the main computer and someone came out to program or flash it,(whatever it is they do when a new computer is installed). No change! New Battery, no change. Up next, replace the body control module and the transfer case module,(should be followed up with replacing several other modules).
I am feeling like I may be getting taken advantage of. The owner of the shop continues to change the story after each fix. Am I overreacting? Should I take it to another shop?
Thanks for reading and any suggestions or advice would be greatly appreciated. The prices have been fair so far.

 

[rockola1971]

File insurance claim. You may very well had a lightning strike to the vehicle. It could be a coincidence to the storm or incidental to it but it sounds like you have grounding damage at the chassis along with most likely module and wiring harness damage. Remember the wiring harnesses are designed to hold up to a steady 15vdc or so, NOT the 1 million volts of lightning. Lightning will burn holes right through the insulation of any cable or wire. Lightning takes ALL paths of resistance (Unlike electricity taking the least path of resistance).
But why the hell is the garage messing with the BCM? It has absolutely nothing to do with your transmission nor engine.
If you have full coverage I would take it to a GM dealership and file a claim with your insurance company. If you did take a lightning bolt to the GM, they will never get it 100% without replacing alot of modules and wiring along with retouching of grounds. What a nightmare.

 

[ribs2k]

File insurance claim. You may very well had a lightning strike to the vehicle. It could be a coincidence to the storm or incidental to it but it sounds like you have grounding damage at the chassis along with most likely module and wiring harness damage. Remember the wiring harnesses are designed to hold up to a steady 15vdc or so, NOT the 1 million volts of lightning. Lightning will burn holes right through the insulation of any cable or wire. Lightning takes ALL paths of resistance (Unlike electricity taking the least path of resistance).
But why the hell is the garage messing with the BCM? It has absolutely nothing to do with your transmission nor engine.
If you have full coverage I would take it to a GM dealership and file a claim with your insurance company. If you did take a lightning bolt to the GM, they will never get it 100% without replacing alot of modules and wiring along with retouching of grounds. What a nightmare.

Unfortunately, I do not have full coverage. I do get the feeling that this shop is chasing their tails. The rebuilt transmission is not adjusted correctly and while I am having the shifting problems I am manually shifting and it is off a bit and I have to wiggle the shifter to make sure it is in gear. I don’t know how far to take this. I am already in it for a good chunk of change. Tough call! It is a nightmare.

 

[ribs2k]

What would you recommend that I have done next instead of the body control module? Should I have the Transfer Case module replaced first? Does the body control module even speak to the transfer case module or the 4 wheel drive module?

 

[rockola1971]

Unfortunately, I do not have full coverage. I do get the feeling that this shop is chasing their tails. The rebuilt transmission is not adjusted correctly and while I am having the shifting problems I am manually shifting and it is off a bit and I have to wiggle the shifter to make sure it is in gear. I don’t know how far to take this. I am already in it for a good chunk of change. Tough call! It is a nightmare.

The only adjustment is in the shifter linkage and thats an easy fix or you may need to replace cable because of cable end connector failure.
Have a watch here:

 

[ribs2k]

The only adjustment is in the shifter linkage and thats an easy fix or you may need to replace cable because of cable end connector failure.
Have a watch here:

Thank you, that is a big help

 

[rockola1971]

What would you recommend that I have done next instead of the body control module? Should I have the Transfer Case module replaced first? Does the body control module even speak to the transfer case module or the 4 wheel drive module?

Next step I would take is all major grounds remove the big 3 and inspect, clean and reattach. I Would even go as far as ohm out the grounds to see if they have nominal resistance values. This should make a burn in the grounding show its ugly head. Then next up a thorough inspection both visual and with an ohmeter of the main harnesses from the PCM. And I do mean thorough. Then the same for all other modules that can be culprits to your various problems.
Your engine and transmission are controlled by your PCM so that is why I would start there first as far as modules.

 

[ribs2k]

Next step I would take is all major grounds remove the big 3 and inspect, clean and reattach. I Would even go as far as ohm out the grounds to see if they have nominal resistance values. This should make a burn in the grounding show its ugly head. Then next up a thorough inspection both visual and with an ohmeter of the main harnesses from the PCM. And I do mean thorough. Then the same for all other modules that can be culprits to your various problems.
Your engine and transmission are controlled by your PCM so that is why I would start there first as far as modules.

Silly question, what is the PCM?

 

[rockola1971]

A very generalized guide:
PCM Controls Engine and Transmission
BCM Controls interior lights, communication to radio for certain features, Power seat settings and control, power window control. Basically creature comforts.
There are various signal outputs from one module to another but generally if you have a transmission/engine control problem, its your PCM or its Harness (fault within) if its not internal to your engine or tranny.

 

[rockola1971]

Silly question, what is the PCM?

Powertrain Control Module. (Aka engine computer, brain, etc.) Its under hood, drivers side fender. You will see a box with a bunch of wiring harnesses plugging into it. Its near your fusebox under the hood.