05 Denali Driver's Seat issues

[Loki223]

Alright, well first post here and i've got to say, i already like this forum better then the GM Fullsize i tried...things are actually laid out and structured.. But beyond that, i'll keep my other comments for somewhere else. Recently picked up a 05 Yukon XL Denali, 178k miles, would be clean if it was cleaned more, but the seats are actually in fantastic condition when compared to just about any other GMT800 with these miles that i've seen. Going through the kinks on her, and getting her back into DD shape. Going to be a spare rig for us, weekend driver, and winter vehicle for the wife. But back to the basics, the driver's seat has no function. Passenger seat has full function. Replaced driver's seat controls on side of seat with a new dorman unit (old controls were broken, so regardless of good or not, they needed replaced) seat still inop. Went under the seat last night with a multimeter, i have good power and ground going to the main connector, as well as the seat controls. That makes me lean towards the seat module. I plan on inspecting it a little closer tonight to see if there is a loose connection or something, but is there anything else i can diagnose while i'm there? Or are there other items i should look into to diagnose before swapping other parts around? I found where i can hot wire the motor to confirm movement at the back of the seat, which i will likely do this weekend. Looks like to replace the module i'll need to pull the seat. I did find a dorman P/N of 590002 which is about $300. Local salvage yard won't let me take the seat module without the seat, and i saw online people programming the seat modules as they might be vin locked? shouldn't it be as simple as finding one with the same options? any help would be appreciated, thanks in advance

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me in this area will chime in.

I can say that several control modules in these trucks are programmed to the vehicle's VIN, but I'm not sure about the seat control module.

If you don't already have a bi-directional scanner, you should pick one up, as it makes diagnosis of issues so much easier (and less costly than the parts cannon). A Tech 2 (~$350) would be a great pick, if you need a bi-directional scanner.

 

[Loki223]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me in this area will chime in.

I can say that several control modules in these trucks are programmed to the vehicle's VIN, but I'm not sure about the seat control module.

If you don't already have a bi-directional scanner, you should pick one up, as it makes diagnosis of issues so much easier (and less costly than the parts cannon). A Tech 2 (~$350) would be a great pick, if you need a bi-directional scanner.

Pics here. So far looking around i like this site. reminds me of CF, lots of knowledge, and people are more concerned about fixing things correctly then badgering people.

New here, not really new

New here, so figured i'd post an intro. Just picked up an 05 Yukon XL Denali. She's a bit of a project, but not really She has some spicy wiring due to the HVAC controls short ciruciting, but that should be fixed by this weekend, just waitng on parts. I've been around a lot of vehicles...

www.tahoeyukonforum.com

 

[Loki223]

So doing some more reading on the module, it appears to control both driver and passenger seats, and i am only having issues with the driver's seat. I will attempt to hot wire the seat motor this weekend and see if the motors move, being that the passenger side works perfectly, i don't believe the module itself to be bad now. But i'm not certain what else the problem could be, might have to look into trying to find a pin out on the controls to be able to check things individually

 

[Loki223]

for reference, found this pretty quickly. should be pretty easy to hot wire things, looks like it might end up being the motors then, but i'll know for sure when i get to playing with my wires. Intersting that this diagram doesn't even show the seat module anywhere in it though....

 

[Sam Harris]

Welcome from Texas! Apologies, I don’t have a suggestion for you, but I think hot wiring it to determine if the motors activate is a good plan.

 

[Loki223]

well, with some jumper wires i was able to get the motor to attempt to move back, however it's already in the full back position. So that tells me the motor is fine. I tried the other pins on the plug at the rear of the seat, but i was just jamming wires so i might not have been good contact, i'll build a better jumper with pins to actually insert and get good connection. I am curious if anyone knows what all the control module under the seat really controls. I have no heated seats in the front (forgot to check to the rear), passenger seat moves and lumbar support works, but driver's seat no controls work. hitting the preprogrammed memory locations moves the mirrors, but did nothing with the seat halfway as expected. I did find the main plug at the bottom rear of the seat last night, but it was getting close to 8 and i needed to eat and take care of a few other things. I just want to get the darn seat to be able to move...the ground on the B pillar looked fine, and the wiring to it seemed fine. Going to try and swing by a wrecker and get a plug so i can make a better hotwire, and provide power directly to the seat and see if it's a ground issue. Tried playing with the connector a bit and no change, i'm thinking if i can provide direct power to it, and get the seats to move i'll remove the seat and inspect the connections and wiring more. This would be a lot easier if there was some sort of override to move the seat, i'd probably have pulled it out last night...

 

[Loki223]

Bumping this up, hoping someone might have some more insight on this

 

[Loki223]

Alright, so for anyone who doubts the theory that you should get AC Delco parts and not store brand, my HVAC system is working nearly perfectly now. 3 resistors frm O'reily's, and 2 blower fans to find ones that work, but the Doorman control unit i ordered off amazon worked great on first one, so that's good. Original controls were shorted internally would be my guess, they were sending a run signal to the resistor, but that didn't change the fact that 1 resistor was bad out of the box and just had the fan blowing constantly, while the 2nd one just didn't work at all. 3rd one, which i replaced in the parking lot at O'Reily's actually worked perfectly out of the box, so finally got a win there. First fan made noise and smoked instantly, so bad manufacturing out the gate. Second one worked perfectly. So now that i have HVAC working and we hit high 80s this weekend....no AC. I'm going to grab a recharge kit while i'm in Idaho today, since our glorious government in the great state of Washington banned freon to private sales....Which is stupid. I found the low pressure plug, but i was curious where the high pressure port is? The low pressure port is on the same line as the only other port i could find which just struck me as odd. I have gauges and was going to run a vacuum on the system to see if it would hold a vacuum or not, but didn't see the second port anywhere so figured i'd ask where it is so i can actually run some diagnostic on the system to find the problem. Chances are the freon leaked out somewhere, my guess is the compressor, but i'd like to know for sure where the issue is before i just throw parts at it...

And i didn't get a chance to mess with the seat. Might try to do something with it this week, as i know i'll be busy this weekend. Swapped out the wheel speed sensor to get rid of the ABS lights on the dash, and yes i will be replacing both hubs up front soon, but i want to get most of the quirks figured out and fixed before i start catching up on the deferred maintenance issues. Won't be driving her much so not to worried about those just yet.

List of known issues,
Driver seat INOP, both front seats heated seats INOP (need to check the rear seats if their heaters work or not)
Front wheel bearings / hubs
Rear defrost tab is broken, i'll get a new rear window at the wrecker sometime this year, low priority
AC not working
OIL pressure sensor needs swapped, that will happen as soon as i have time
Third brake light INOP, likely just needs bulbs, but also low priority. will likely swap out to an LED unit
Fuel level sender inaccurate, not a big deal but an issue. read at 3/4 when full, so will need to drop the tank at some point and swap out the sender unless there is a common problem elsewhere that causes that

I think i'd like to be able to focus on the seat and get that working so the wife can drive it, then i can focus on maint. issues like the oil pressure sensor and the wheel bearings so it's safe to drive. Then i'll finish off the rest of it pretty quickly

 

[Sam Harris]

Alright, so for anyone who doubts the theory that you should get AC Delco parts and not store brand, my HVAC system is working nearly perfectly now. 3 resistors frm O'reily's, and 2 blower fans to find ones that work, but the Doorman control unit i ordered off amazon worked great on first one, so that's good. Original controls were shorted internally would be my guess, they were sending a run signal to the resistor, but that didn't change the fact that 1 resistor was bad out of the box and just had the fan blowing constantly, while the 2nd one just didn't work at all. 3rd one, which i replaced in the parking lot at O'Reily's actually worked perfectly out of the box, so finally got a win there. First fan made noise and smoked instantly, so bad manufacturing out the gate. Second one worked perfectly. So now that i have HVAC working and we hit high 80s this weekend....no AC. I'm going to grab a recharge kit while i'm in Idaho today, since our glorious government in the great state of Washington banned freon to private sales....Which is stupid. I found the low pressure plug, but i was curious where the high pressure port is? The low pressure port is on the same line as the only other port i could find which just struck me as odd. I have gauges and was going to run a vacuum on the system to see if it would hold a vacuum or not, but didn't see the second port anywhere so figured i'd ask where it is so i can actually run some diagnostic on the system to find the problem. Chances are the freon leaked out somewhere, my guess is the compressor, but i'd like to know for sure where the issue is before i just throw parts at it...

And i didn't get a chance to mess with the seat. Might try to do something with it this week, as i know i'll be busy this weekend. Swapped out the wheel speed sensor to get rid of the ABS lights on the dash, and yes i will be replacing both hubs up front soon, but i want to get most of the quirks figured out and fixed before i start catching up on the deferred maintenance issues. Won't be driving her much so not to worried about those just yet.

List of known issues,
Driver seat INOP, both front seats heated seats INOP (need to check the rear seats if their heaters work or not)
Front wheel bearings / hubs
Rear defrost tab is broken, i'll get a new rear window at the wrecker sometime this year, low priority
AC not working
OIL pressure sensor needs swapped, that will happen as soon as i have time
Third brake light INOP, likely just needs bulbs, but also low priority. will likely swap out to an LED unit
Fuel level sender inaccurate, not a big deal but an issue. read at 3/4 when full, so will need to drop the tank at some point and swap out the sender unless there is a common problem elsewhere that causes that

I think i'd like to be able to focus on the seat and get that working so the wife can drive it, then i can focus on maint. issues like the oil pressure sensor and the wheel bearings so it's safe to drive. Then i'll finish off the rest of it pretty quickly

If you don’t mind doing a patch job on the defroster tab, there’s a great product for this (and I believe, the only one that actually works):
Frost Fighter Rear Window Defroster/Defogger Tab Bonding Repair Kit 2000 https://a.co/d/4XcUrrr

It is a little expensive, but I believe that’s due to it containing actual silver in the kit. Definitely worth it IMHO.

 

[Loki223]

If you don’t mind doing a patch job on the defroster tab, there’s a great product for this (and I believe, the only one that actually works):
Frost Fighter Rear Window Defroster/Defogger Tab Bonding Repair Kit 2000 https://a.co/d/4XcUrrr

It is a little expensive, but I believe that’s due to it containing actual silver in the kit. Definitely worth it IMHO.

Oh that's just perfect. $100 cheaper then replacing the rear glass, and easier since i don't have to pull the glass off, so definitely worth a shot. Looks pretty easy to do, so a penny saved is a penny earned right? Got that ordered up so maybe i'll be able to take 15 minutes and do that this weekend

 

[Sam Harris]

Oh that's just perfect. $100 cheaper then replacing the rear glass, and easier since i don't have to pull the glass off, so definitely worth a shot. Looks pretty easy to do, so a penny saved is a penny earned right? Got that ordered up so maybe i'll be able to take 15 minutes and do that this weekend

It’s worked great for me. Good luck!

 

[Loki223]

Yeah, now the main thing i need to find time to do is figure out wtf is going on with the driver's seat. Fingers crossed it's just a bad connection somewhere, hoping to play with it this weekend but i know this weekend is a busy one for us

 

[Sam Harris]

Good luck man. I know the feeling. I have 2 fairly significant projects on both vehicles needing done, but between the kiddo, and the dogs, it’s pretty rough finding time as a single dad.

 

[Loki223]

Alright. So first of all. Shame on everyone who has read this and not thought to point out the obvious. Seat doesn't move? Need to access the wires under it to diagnose? Just pull the bottom of the seat off. Why are you trying to make this complicated and hot wire stuff. Just pull the seat and gain full access to the undercarriage. Stumbled onto this video and couldn't help but think look at all the room for activities.

So now I'm hoping that tomorrow the dump truck drivers are good at their job and spread everything how i know they should be able to so that i don't have to spend the next 2 nights fixing their job so that everything is ready for Friday and my weekend projects. Because if they do their job, i get to jump under the seat tomorrow night and hopefully get the power seat working once i can diagnose the issue that's at that plug

 

[Loki223]

So i found some time to do a couple things this weekend. Swapped out the third brake light, and now the driver's seat works! I mean yeah, it could be all my fumbling with the main harness that made it work, but I'm going with the third brake light being the culprit.


I do plan on pulling that connector some time, cleaning it and reinstalling it to prevent future issues, but at least that problem is solved. Pretty sure it's the ground connector on the main harness. Got all my functions back. Also fixed the rear window defroster, and diagnosed the AC issues to be the compressor not kicking on. Plus i ordered new hubs so next weekend i should be able to get it 100% driving again, and then i'll work on the AC to make it comfortable and driving.

 

[Breeze]

So i found some time to do a couple things this weekend. Swapped out the third brake light, and now the driver's seat works! I mean yeah, it could be all my fumbling with the main harness that made it work, but I'm going with the third brake light being the culprit.


I do plan on pulling that connector some time, cleaning it and reinstalling it to prevent future issues, but at least that problem is solved. Pretty sure it's the ground connector on the main harness. Got all my functions back. Also fixed the rear window defroster, and diagnosed the AC issues to be the compressor not kicking on. Plus i ordered new hubs so next weekend i should be able to get it 100% driving again, and then i'll work on the AC to make it comfortable and driving.

So on the seats I had the same issue no movement on driver's seat and ne heated seat on either. Tracked mine down to a bad connection under driver's seat. I simply wired the main hot(10 or 12 ga red wire) together outside the connector. Then about a year later the ground side burnt up and did the same with that. I just used a butt connecter as I have no plan of removing seat. Also did not have to pull seat bottom to do it, just from the back seat.. hope this helps!

 

[adventurenali92]

Wait you have a 2005 Yukon XL Denali and your front seats aren’t heated?! That’s fishy….. every GMT800 Denali package truck and Yukon I’ve ever seen anywhere has 12 way power adjustable heated front seats……

 

[Loki223]

Wait you have a 2005 Yukon XL Denali and your front seats aren’t heated?! That’s fishy….. every GMT800 Denali package truck and Yukon I’ve ever seen anywhere has 12 way power adjustable heated front seats……

I mean, techinically it didn't have heated seats until i got the connector fixed, then it did again. Unless you are talking about someone else, but i don't think i ever said it wasn't equipped with them, just wasn't functioning correctly which is why i figured it was wiring or the front seat computer under the driver's seat. My issue did turn out to be the main harness which is common, i'm just used to picking up somene else's junk to find out the problem was defintiely not the common issues. Hopefully soon i'll have some time to work on it some more so we can start driving it. Need to find a couple of hours to do both front hubs one of these days, but being a spare vehicle, it's a low priority thing for now

 

[adventurenali92]

I mean, techinically it didn't have heated seats until i got the connector fixed, then it did again. Unless you are talking about someone else, but i don't think i ever said it wasn't equipped with them, just wasn't functioning correctly which is why i figured it was wiring or the front seat computer under the driver's seat. My issue did turn out to be the main harness which is common, i'm just used to picking up somene else's junk to find out the problem was defintiely not the common issues. Hopefully soon i'll have some time to work on it some more so we can start driving it. Need to find a couple of hours to do both front hubs one of these days, but being a spare vehicle, it's a low priority thing for now

I misunderstood your post. The way it read sounded like it didn’t actually have heated seats. That’s why I was confused. My bad.