Pappyvtx

Evening all. I decided to swap my drivers seat out tonight with a matching seat from an 08 Tahoe. (Nice Match) hooked up the main junction harness to the replacement seats and the "fwd/up/down controls" just made a click noise in any direction that I moved them. The backrest tilt control worked and the lumbar inflated and deflated properly. NOW, all I did was tip the seat onto its back to check the motors, and now, NOTHING is working. I DID check all my fuses, all good.I DO have power to the harness at the union and at my switches. 12.23vdc. There is a module under the seat that it looks like all the motors and controls go through. Is it likely that this module has gone bad? Does it actually control the various seat functions? I thought about trading the one in my old seat to the replacement seat, but am afraid that there might be something that may have fried the replacement? ( The reason I swapped seats is the old one no longer heated on the back and the lumbar no longer inflated) Thanks all! ( oh yes, I DID check all the plugs under the seat for pulled/loose connections)

a55bruce

There are 2 power circuits feeding the memory seat module. Re-check the fuse "DSM", and the circuit breaker "DRIVER SEAT 2". Also, check for a good ground connection for the seat & memory module wiring.

Pappyvtx

a55bruce , Thanks for the reply. DSM fuse is good. As for the DRIVER SEAT 2 Breaker, where would that be? Can't find a reference to it anywhere. I did check the voltage on the brown power plug on the module and have a solid 12.55 vdc across the hot wire and the 2 ground wires in it.

a55bruce

The circuit breaker should be located in the left instrument panel junction block. The power you're measuring at the power plug should be on pins 5 & 6, grounds on pins 1 & 4. (If we're talking about the same plug) Pin 3 should have a 12V reference signal. I was thinking your problem was a ground issue because of the complete failure when you tipped the seat back. This makes it sound like a loose connection somewhere. I'm running out of ideas....

Pappyvtx

Found the issue(s)!!!! Primary issue was the seat module! Replaced it and most of the functions worked correctly! The second issue ( not asked about in my original post) was that the worm screw, that makes the seat move upward, was froze/bound up. Finally got it freed, lubricated all worm screws with white lithium grease, and moved seat in all directions. Heated seat works properly now, position memory, lumbar, all work correctly. Thanks a55bruce for the input!

in2pro

Pappyvtx Was the seat removal pretty straight forward? The rear lift of mine stopped working, I hear the motor run but the seat does not tip forward...

Pappyvtx

in2pro, The front drivers seat was the one I replaced. But, it was VERY straightforward; 2 nuts on the front, 2 bolts on the back and a nut for the seat belt, then a quick release on the harness under the seat and it was out. Something to note, for those who haven't ventured into these, the nuts are like a reverse torx but a 15mm socket worked great and the bolts on the rear have the same design. An 11mm socket will fit with some effort and a 12mm will work loosely. If the bolts are exceptionally tight, use the 11mm. If they break loose fairly well, use the 12mm for less aggravation. I would imagine that the other seats would come out as easily.

Pappyvtx

in2pro, I just thought of something...if you take your seat out and find the correct motor underneath for the rear lift, there are little (transfer cases??) that have the gearing for the worm gears that operate the different functions. My "LIFT" worm gear was stuck hard! I have to open the gearbox so the gears wouldn't touch, then take a rag (very important) and wrap around the worm gear, then used a pair of pump pliers and worked the gear back and forth kinda hard and got it to free up. Then use some white lithium grease to lube the gears. ( I didn't use the rag at first and wound up marring the worm gear!) Might save you some money if the motor isn't bad! =-)