Seat backs not reclining

Did you try scrap yard?I bought for $50 seat.

The gears for the recliner has been misaligned/broken. Disassemble and look for broken parts. Refer to service manual to realign,

It sounds like the inside of the recliner knob is stripped out. If you go to your local GM dealership and give them your VIN number they can order you a new one. Here is the removal and installation directions.
Driver or Passenger Seat Recliner Handle Replacement Removal Procedure

1. Use a flat-bladed tool to remove the plastic center cap from the center of the recliner handle.
   
   
2. Pull the recliner handle off the shaft.

Installation Procedure

1. Install the recliner handle on the recliner shaft.
   
   
2. Push the recliner handle firmly onto the recliner shaft until fully seated.
3. Install the plastic center cap into the center of the recliner handle.

Hope this helped please hit the accept button and positive feedback is appreciated.

I had the same seat recliner/raiser problem and worked around it. There is a gear shaft that runs across the back of the drivers seat just behind the split between the seat and seat back. It is broken.

The motor that runs the gear shaft is located on the side of the seat closest to the drivers' door. It works fine but only moves the gears on the drivers door side of the seat. On the console side
of the seat the gear doesn't turn at all because the shaft is broken where it meets the gear on that side. You can see the end of the gear shaft on the outside of the seat hinge on the console side and if the shaft is broker it will not move when the lever is pushed to raise the seat back.

I removed the seat (basically pull off the plastic button covers, remove four seat bolts, and disconnecting two wiring harness clips) and I was able to raise the seat "manually" as follows:

On the very end of the gear shaft itself you'll see a small alignment groove in it that would normally align with another groove on the seat hinge frame. (I suppose when they are aligned, that is the factory setting for the upright seat back position)

I put a straight slot screwdriver in the groove on the gear shaft and used a hammer to drive the gear clockwise (to raise the seat back; you'd go counter-clockwise to lower it).
With each hammer strike the gear moved a little bit until the grooves were aligned. The angle of the seat back raised a bit with each clockwise movement of the gear shaft. (I actually went a little further than the alignment of the markers to assure the seat was raised far enough). When I was satisfied with the seat back position, I reconnected and rebolted the seat.

Anyway, the seat back is now raised to about where I wanted it. The shaft is still broken, of course, and the vertical motor is now bound up and doesn't work... so this is now my permanent driving position... but it's much better than driving with the seat reclined!
And for a 1998 Avalon XLS with over 300,000 miles, I can certainly live with that.

Hope this helps someone else. I'll be pleased to answer any questions you may have.

You must remove the motor, move the seat to the desired position and then reinstall the motor to lock the seat in the position.

The first place to start would be to have the dealer or someother qualified repair shop , that has a professional scan tool read DTC'S - diagnostic trouble codes in the driver seat module ! The seat adjuster motors are controlled by the driver seat module through the adjuster motor control circuits. In an inactive state both of the motor control circuits are grounded within the driver seat module. In an active state the driver seat module switches the appropriate motor control circuit to battery positive voltage. The direction of the adjuster motor rotation is determined by which of the motor control circuits is switched to battery positive voltage while the other remains grounded. During adjuster motor operation the driver seat module also monitors the current flow through the motor control circuits.
DTC B1770, B1775, B1780, B1785, B1790, B1805, or B2415
B1825 , B1850, B1860, B1960, B2355, B2365, or B2375
B3962
Memory Seat System Components
The memory seat system consists of the following components:
• Power seat switch assembly
• Memory recall switch assembly
• Horizontal adjuster motor
• Front vertical adjuster motor
• Rear vertical adjuster motor
• Recline adjuster motor
• Driver seat module
• Driver door module
• SEAT 30A circuit breaker
Memory Seat System Description
Battery voltage is supplied to the driver seat module through the power seat circuit breaker. The driver seat module supplies the seat adjuster switch assembly with a battery positive reference voltage. While the seat adjuster switches are in an inactive state the switch contacts are closed to the adjuster switch ground circuit. When a seat adjuster switch is pressed to an active state the switch contact is closed to the reference voltage circuit. Battery voltage on a switch signal circuit indicates to the driver seat module the switch status is active. Each seat adjuster motor is controlled by the driver seat module through 2 motor control circuits. While the seat adjuster motors are in an inactive state the motor control circuits are closed to ground circuit contacts within the driver seat module. The driver seat module operates the seat adjuster motors by switching one of a motor's control circuits to battery voltage. The seat adjuster motors are bidirectional and the direction of adjuster motor rotation is determined by which of the adjuster motor control circuits is switched to battery voltage while the other remains grounded.

Memory Set/Recall Operation
The seat adjuster motors are equipped with internal position sensors. The adjuster motor position sensors are monitored by the driver seat module and are used to determine the seat position when storing or recalling memory settings. The horizontal, front vertical, and rear vertical adjuster motors use hall effect type position sensors. The hall effect position sensors are supplied with battery positive reference and ground circuits from the driver seat module. The position sensor signal circuits are supplied battery positive voltage through a resistor them monitored within the driver seat module. During adjuster motor operation the hall effect position sensor provides a single pulse for every revolution of the adjuster motor shaft. The driver seat module counts the pulses from the position sensor signal circuits to determine the adjuster motor positions when storing or recalling memory seat position settings. The recline adjuster motor is equipped with a potentiometer type position sensor. The recline motor position sensor is supplied with it's own 5-volt reference ground circuits from the driver seat module. The recline position sensor signal circuit is referenced from ground within the driver seat module. The signal voltage monitored by the driver seat module ranges from 0.39 - 4.58 volts and is determined by the wiper location on the resistor within the recline motor position sensor. The recline motor position sensor signal circuit voltage level is used by the driver seat module to determine the seat recline position when storing or recalling memory seat position settings.
The memory recall switch assembly on the driver's door provides inputs to the driver door module. Battery voltage is supplied to the memory

I have G35 coupe and it's on a recline position. The car seat won't come up?

Use some penetrating lubricant on all pivot points and levers around the recline mechanism, and let the lubricant sit overnight. In the morning, try to work the recline mechanism free. (The vehicle is quite old at this point, and likely parts in the interior need lubrication. These parts should be lubricated annually.)

Because that switch is broken and stuck in the recline mode.

check the adjusting bar on the pass. door side of seat.