Can one manually move power seat backward? Swap motor?

[B8Buckeye]

I swapped power B8 S4 seats into my B8 A4 Avant, and the driver's seat won't move backward. The motor works otherwise and moves up/down/forward, but it won't move backward. If the seat gets moved forward, it won't go back again.

Is there a way to manually move the seat back?

If not, is there a way to swap the motors from the driver's and passenger's seats?

If not, can the driver's seat motor easily be replaced with another driver's seat motor?


I'm going on a long road trip and would really like to move my seat back.


Thanks!

[Smac770]

Curious, you have a lot of text about your car, but not the model year. Though 2011 or 2012 is a certain guess given avant and ZF8.

By "S4 seats", I presume you mean S sport seats, with the fixed headrest? Though it seems the seat adjustment electronics are common across the standard, sport, and S sport seats in the 8K.

https://audi.7zap.com/en/usa/audi+a4.../9/959-959020/
We see the rake/tilt motor (2), the height motor (3), the backrest motor (4), and the longitudinal motor integrated with the seat rails (1). It refers to the different page:

https://audi.7zap.com/en/usa/audi+a4.../8/881-881010/
Item 6. So different parts for left and right, but the same part for the three different style of seats. But since the motor is integrated, that's certainly a larger task than just a motor swap.

https://audi.7zap.com/en/usa/audi+a4.../9/971-972012/
Here we see the wiring harness for the motors. Are these seats memory equipped? If memory equipped, the motors are connected to the memory control module. If not memory equipped, they are driven directly by the toggle switches. It could be the toggle switch has a bad contact. If memory equipped, you should be able to monitor the activation of the switches and check for DTCs in the memory seat control module (address 36).

I don't have any idea how you'd move the seat manually, such as if it was unpowered, or just not working as in your case.

[B8Buckeye]

Curious, you have a lot of text about your car, but not the model year. Though 2011 or 2012 is a certain guess given avant and ZF8.

By "S4 seats", I presume you mean S sport seats, with the fixed headrest? Though it seems the seat adjustment electronics are common across the standard, sport, and S sport seats in the 8K.

https://audi.7zap.com/en/usa/audi+a4.../9/959-959020/
We see the rake/tilt motor (2), the height motor (3), the backrest motor (4), and the longitudinal motor integrated with the seat rails (1). It refers to the different page:

https://audi.7zap.com/en/usa/audi+a4.../8/881-881010/
Item 6. So different parts for left and right, but the same part for the three different style of seats. But since the motor is integrated, that's certainly a larger task than just a motor swap.

https://audi.7zap.com/en/usa/audi+a4.../9/971-972012/
Here we see the wiring harness for the motors. Are these seats memory equipped? If memory equipped, the motors are connected to the memory control module. If not memory equipped, they are driven directly by the toggle switches. It could be the toggle switch has a bad contact. If memory equipped, you should be able to monitor the activation of the switches and check for DTCs in the memory seat control module (address 36).

I don't have any idea how you'd move the seat manually, such as if it was unpowered, or just not working as in your case.

Thanks for the response...

2011 Audi A4 Avant that came with sport seats. I replaced the sport seats with the Magma S sport seats with the fixed headrest.

The seats are memory seats, but I was never able to get the memory modules to work after swapping the S sport seats into the car. Also, when I first installed the seats, all functions worked, but the backward function was noticeably slower than the forward function. At one point, the backward function just stopped.



So, it appears that the problem is with part number 8K0881183A, BUT this motor works in moving the seat forward. It only malfunctions when trying to move the seat backward. It sounds like it could be a possible switch issue, but I had my mechanic check the switches, and he said they were working.

I suppose the motor could work in one direction but not the other?


Here is the motor available on Ebay.

I see that you said it was integrated into the rail, but with them being sold separately, I wonder how difficult/easy it would be to swap one of these motors. If it's the motor, it seems swapping it out would fix my issue.

[Smac770]

https://www.ecstuning.com/b-genuine-...ft/8k0881183a/

So it's sitting there, but there's no procedure from Audi for swapping just the motor, since it's an integrated single part. Is there any zero point, calibration, etc. No such documentation.

Locking but no longer unlocking is a common issue in the door lock actuator. But in that instance, there's two motors, one for each action. Here we see there's just one motor. It moves simply depending on if 12v is applied to one pin or the other pin. So it would seem odd for the motor itself to have an issue going the opposite way.

As for the driver's seat memory module, probably had component protection on it. There's other seat swap threads; you could see in them if component protection is an involved issue.


I'd get the seat up where you can access the motor plug, back probe it and check the voltage present when moving the seat in either direction. In a no-memory config, 12v and ground go directly to the switches panel. No press, both motor contacts are connected to ground. Press the switch one way, and one motor contact is switched to 12v. Press the switch the other way, and the other motor contact is switched to 12v. I find it unlikely the motor will work fine in one direction but not the other, but maybe that is an actually possible failure mode. It's a super simple circuit; maybe even the issue is not 12v but the ground contact.

[B8Buckeye]

https://www.ecstuning.com/b-genuine-...ft/8k0881183a/

So it's sitting there, but there's no procedure from Audi for swapping just the motor, since it's an integrated single part. Is there any zero point, calibration, etc. No such documentation.

Locking but no longer unlocking is a common issue in the door lock actuator. But in that instance, there's two motors, one for each action. Here we see there's just one motor. It moves simply depending on if 12v is applied to one pin or the other pin. So it would seem odd for the motor itself to have an issue going the opposite way.

As for the driver's seat memory module, probably had component protection on it. There's other seat swap threads; you could see in them if component protection is an involved issue.


I'd get the seat up where you can access the motor plug, back probe it and check the voltage present when moving the seat in either direction. In a no-memory config, 12v and ground go directly to the switches panel. No press, both motor contacts are connected to ground. Press the switch one way, and one motor contact is switched to 12v. Press the switch the other way, and the other motor contact is switched to 12v. I find it unlikely the motor will work fine in one direction but not the other, but maybe that is an actually possible failure mode. It's a super simple circuit; maybe even the issue is not 12v but the ground contact.

So, I found a replacement rail system with the motor included. Any ideas how to remove the seat from the car with it moved too far forward to access the front rail bolts? Can the seat be removed from the rails while still in and attached to the car??

Thanks

[Smac770]

No idea. If the seat is that far forward, can you get hands on the motor on the rails bracket? With the seat moved upward as much as possible, you might be able to. Get some probes on there and see if 12v is showing up. If not, maybe get some new lead wires on the motor that you can jump to 12v to move it, once you figure which wire you need 12v on to make it move backwards. It looks like from the ECS pics that the plug on the motor would be to the inside, and on the rear side of the cross rail. Might make it easier to work in there with the rear seat bench removed.

Apparently a last resort path is to remove four bolts that hold the lower frame to the rails. They are two on each side, kind of in the middle. You'll have to remove the controls trim to get the outside pair of bolts; you'll have to go under the seat to get to the tunnel side bolts.

[B8Buckeye]

No idea. If the seat is that far forward, can you get hands on the motor on the rails bracket? With the seat moved upward as much as possible, you might be able to. Get some probes on there and see if 12v is showing up. If not, maybe get some new lead wires on the motor that you can jump to 12v to move it, once you figure which wire you need 12v on to make it move backwards. It looks like from the ECS pics that the plug on the motor would be to the inside, and on the rear side of the cross rail. Might make it easier to work in there with the rear seat bench removed.

Apparently a last resort path is to remove four bolts that hold the lower frame to the rails. They are two on each side, kind of in the middle. You'll have to remove the controls trim to get the outside pair of bolts; you'll have to go under the seat to get to the tunnel side bolts.

Thanks for all your help. It appears to be a switch problem as swapping the wire for the forward and backward control allowed the seat to be moved backward to a comfortable position.

I'll be searching for a replacement switch now.


Thanks again!

[Smac770]

Excellent, as I imagine that was the best case scenario.

You might also pull the plug on the seat controls and reinsert it; maybe pin just making a bad connection. There's a 6-pin plug that supplies the power and ground to the switches, then a 10-pin plug that connects to the motors (for the no memory version).

For no driver's seat memory, the driver's seat controls unit is 8K0 959 747, with plugs as above. For with driver's seat memory, the driver's seat controls unit is 8K0 959 747 B, with only 5 wires on a single plug as it's just logic control.

Example, https://wolfautoparts.com/seat-adjus...7-ps17100.html

Note, the two switches have caps on them; you'll want to take those off your old one to put on your replacement.