Seat not working?

if this vehicle has had the air bag deployed then the seat module must be reprogrammed because there is a code stuck in memory. check around parking brake where harnesses are and see if any are chafed or cut that may be a problem. finally scan for codes as it may show a code. Here is a guide to help us with the CAN scan

https://youtu.be/InIlnsjOVFA

Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.

I have read the posts here about this problem. Driver power not working. Adjustable pedals not working. I have pulled off the power seat switch and there is some power to the switch.

What does "some power" mean? Check the red wire to the power seat switch. It should have 12 volts all the time. To be most accurate, that should be measured by back-probing the wire with the connector plugged in. Alternately, a test light works better for this test, but if all you have is a digital voltmeter, that will be okay too.

Red does have power. What I meant by "some power" was there was not any power to any of the other wires, just the one.

Dandy. Now the potential problem is there can be a break in the wire with just one tiny strand left, and that is enough for a digital meter to detect 12 volts, but it's not sufficient to pass the amount of current needed to run a motor. If you tested the wire with a test light, those draw more current and we can believe it. To be safe, and to insure we are not glossing over a clue, test that wire while the switch is plugged in and you activate one of those switches. Either that 12 volts is going to stay there, or it is going to drop close to 0 volts. If it drops to 0 volts, we have to treat that red wire as not having 12 volts. This may seem like overkill, but it is exactly the type of mistake that sends experts down the wrong path.

There are actually 12 switch contacts built into the driver's seat switch assembly, and we know they did not all fail at the same time. Also, there are three motors, and they also did not fail at the same time. That only leaves the ground circuit as the source of the defect. We can use any of the three circuits for testing. I am going to pick the forward/backward switch, just so I can tell you which wires to probe. These next tests must be done with the switch plugged in.

Back-probe the tan and the light green wires. Both will have 0 volts when the switch is released. Now, while watching one of those wires, move the switch in one direction, then the other direction. In one of those directions you should find 12 volts on the tan wire, and 0 volts on the light green wire. In the other direction, you should find 12 volts on the light green wire and 0 volts on the tan wire. If you find 12 volts on both wires at the same time, regardless of which way you push the switch, the ground wire has a break. If that is what you find, measure the voltage on the black wire while the switch is pressed and you have that 12 volts on the tan and light green wires. If you find 12 volts on the black wire, there is a break in that wire or where the wire is bolted to the body, near the base of the left "B" pillar. If you find 0 volts on the black wire, either there is break inside the switch, (very uncommon), or that terminal is not making good contact.

Driver's power seat, adjustable pedals not working.
When you push memory seats positions, mirrors will adjust, but the seat or pedals do not. i have power at the seat switch.

12+ volts on the tan wire when switch pushed forward. 12+ volts on the green wire when pushed to the rear. 0 on both when idle.

check routing of harness under seat as that has been a problem on earlier models also check for good connection at switch. you may have to take that area off to check it the pedal ground is non HVAC on right hand side see if it is a good connection . finally have a mechanic scan for codes. one other thing check grounds on engine for no corrosion's. I have also included a tip which others have found see picture.

Seat Switch plug

What did you find on both wires when the switch was pressed one way? If you found 12 volts on both at the same time, you should have also found 12 volts on the black wire. Check that black wire. If you see any voltage, even if it's less than 12 volts, (but not 0 volts), there is a break in that black wire.

The current alternated between the two seat switch positions when activated. When you say black wire, do you mean the gray with black
Stripe. When I connect the purple + and gray /black (-) I get 12+. Is this correct in what you asking?

There's no purple wire on my diagram. I suppose there could be a white tracer on the black wire, but that isn't shown on my diagram.

To double-check, your test light clip lead or meter negative probe should be on ground, meaning a paint-free point on the body. This way we're taking voltage readings AT a point in the circuit, as opposed to between two points. Those are just two different ways of doing this, but we have to be sure we're both doing it the same way.

Measure the voltage on your black / white wire while you activate the switches. Do you see anything other than 0 volts at any time?

Drive side power seat just stopped working and is locked in a position for wife who is shorter than me

Do you hear the motor trying to run when you pull the switch? Check fuses.

Just checking, did you get the picture I attached of the power seat plug showing the wire colors? Just want to make sure I'm working in the right spot..

The motor does not run. Reading the manaul the dsm fuse operates the seat and remote start. The remote start still works but I will check the fuse

I see eight wires in it, which is correct. Check where the wires go to. The wires must go to the three motors under the seat. There is another version that is for heated / climate-controlled seats. I don't know how many wires are in that plug.

IF you can get to the connector for the motor under the seat. Get a test light and see if when you pull the switch that you are getting power to the motor.

Ok, Here is the results,

with - line grounded on frame and using the + tip to check current at each wire.
With each switch activated individually...(8 positions)

Purple - Hot

Tan - Seat forward 12+
Lt Grn - Seat back 12+

Grn/Wht - Seat back Recline 12+
Gray/Blk - Seat back forward 12+

Yellow - Seat bottom back up 12+
Lt Blue - Seat bottom back down 12+

Dk Blue - Seat bottom front down 12+
Dk Green - Seat bottom front up 12+

I also noticed that when activating a switch and "holding" that position, not only did that corresponding
wire show 12+, but all other positions showed 10.7 volts at the same time. Apparently, no ground at the switch?

Yup. Without going back to the diagram, if you have 12 volts on multiple wires when a switch is activated, you're missing the ground. As I recall, the ground wire is bolted to the "B" pillar next to the driver's seat. I suspect you'll have to pop off a plastic trim cover and / or pull up the carpet.

A better way to verify this, without even having to worry about wire colors, is to measure the voltage across the two wires right at a motor's connector. If you're finding 10.7 volts on the ground wire, you're going to find the remainder of the 12 volts across the motor. That will be less than two and a half volts, which is not enough to make a motor run.

It seems every other function of seat works. When trying to apply more or less lumbar, nothing happens and lumbar just makes a motor working sound. It will move up and down but just not inflate.

Any ideas? How hard of a fix? Are there airbags in the seat which make it tricky to work on? It's a new truck for me.

either get a manual or rent one on site here for a week so you can print the instructions out probably time consuming mostly......

Pulled the trim. Inspected the grounds. Traced the black wire in the harness (under the sill plate) to where it turns to go under the seat. checked the ground to that point. Shows a good ground when probing the wire.

Thanks for your kind reply, though that's not exactly an answer to the issue. After further searching I've found out a bit more regarding a cheap plastic piece that could have broken. Shouldn't be a surprise as its American made.

Then there's only three possibilities. The terminal for the ground wire is stretched and not making good contact with the mating terminal. There's a break inside the switch assembly, most likely where the ground terminal is soldered to the circuit board, or all three switches are bad. That last one is not very likely.

How do I isolate these down to one.

"There's a break inside the switch assembly, most likely where the ground terminal is soldered to the circuit board"
Are we talking about the power seat switch here? No ground present at the switch.

I agree I don't believe all three seat adjuster switches are bad (in 1 assembly).

I have similar 2007 Yukon Denali driver's seat lumbar failure problem. where can I get this repair manual you mentioned. I would like to rent one for a while to research my seat failure issue.

You should be able to pop the switch apart, then expect to find the switches soldered to some type of circuit board. Look at the terminal that corresponds to the black / white wire and see if it is loose where it is soldered or crimped to the board.

Even easier, find a switch at a salvage yard and plug it in to try it.

Here is the repair manual, I found more info in the diagrams below.

https://www.2carpros.com/manuals/manuals.php

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

I have a power seat that won't go up or down in the back. I have power and believe that the worm gear is stuck in the up position. How would i 1) get to it and 2) how would i get the worm gear past it's bound state.

the seat has to be removed, coverings removed to access the motor. I doubt it is the gear. most likely failure is the motor itself.

Roy

The motor wants to turn and i see the worm gear trying to turn when i hit the button.

The driver's side power seat won't go forward or backwards anymore. It is stuck in the far back position. All the other power functions for the seat still work. The dealer wants over 300 dollars just to diagnose the problem!!! I hate to think of paying that amount just to replace a switch or motor! Is there any way to move the seat forward without the power?? I can still drive it, but my wife is just too short to reach the wheel and pedals, even with the power pedals all the way up!

Testing requires the use of a GM compatible scan tool, may shops have scanners that can be used, These systems have a DDM, data comunication lines and BCM, so to get the right answer, you need to read "B" and maybe "U" codes. About the only thing you can try is unplug the connectors and re-plug.

i have a 2003 gmc yukon xl and the electric seat would not go back when exiting the auto it would go forwards now it is all the way back and wont move any place

check your fuses and relays as it may be blown and not letting any power go to the switch. if those are ok, then take it to a pro wher ehe can check switches, motor, or cables. Also make sure nothing is in the way like a pop can or foreign object.