Power Seat Motor: Description and Operation
Removing Front Seat with Faulty Seat Forward/Back Adjustment Motor or Control Module
Test the seat forward/back adjustment motor (V28) / (V31) or control module (J136) / (J521).
• Follow all safety precautions when working on pyrotechnic components. Refer to => [ Restraint System Components ] Description and Operation.
• Before handling pyrotechnical components (for example, disconnecting the connector), the person handling them must "discharge static electricity". For example, by briefly touching the door striker pin.
- Move the seat as far up as possible.
• Check electrical and electronic components and wires before removing seat further to avoid unnecessary repair costs.
- Perform the following tests:
• Check the fuse.
• Check the voltage at the connector station and perform fault finding if necessary.
• Check the voltage to the control module.
• Check the voltage to the seat forward/back adjustment motor (V288).
- Replace the fuse if faulty.
- If there is no voltage at the connector station, repair or replace the wire.
- Replace the seat pan lower frame together with seat forward/back adjustment motor. Refer to => [ Upper Seat Frame ] Upper Seat Frame.
- Replace the memory seat/steering column adjustment control module (J136) or the passenger memory seat control module (J521) is faulty. Refer to => [ Memory Seat/Steering Column Adjustment Control Module ] Memory Seat/Steering Column Adjustment Control Module.
Removing a faulty seat forward/back adjustment motor (V28) / (V31)
Before handling pyrotechnical components (for example, disconnecting the connector), the person handling them must "discharge static electricity". For example, by briefly touching the door striker pin.
- Turn the ignition on.
- Disconnect the battery ground cable with the ignition switched on.
- Disconnect the electrical harness connectors at the coupling station. Refer to => [ Harness Connectors, Disconnecting and Connecting ] Harness Connectors, Disconnecting and Connecting.
- Connect Airbag Adapter (VAS 6281). Refer to => [ , Disconnecting and Connecting ] Airbag Adapter (VAS 6281), Disconnecting and Connecting.
- Remove the bolt - 3 -.
- Remove the seat position sensor - 2 - from the seat pan lower frame - 1 - at the hooks and move the electrical wire to the side - arrow -.
- Disconnect the front safety belt latch connector. Refer to => [ Disconnect the connector and free up the wire ] Front Belt Latch.
- Disconnect the electrical connector on the seat forward/back adjustment motor.
- Remove the bolt - 3 -.
Danger of damaging the threaded the holes or the bushing in the bearing points (connecting the upper and lower frame).
A second technician is needed to push on the seat via the backrest while removing the following screws.
- Remove the bolts - 2 -.
- With a second technician, separate the upper seat frame - 1 - from the lower frame - 4 - and remove from the vehicle.
• Seat without the cushion, cover and backrest is illustrated.
- Make sure the bushings - 1 - and the bearing points (connection upper and lower frame) - 2 - are not damaged.
• The bushings cannot be replaced with workshop materials.
• If the bushings are damaged, the corresponding assembly parts must be replaced.
- Remove the bolts for the seat rail to the bracket.
- Remove the screws - 2 - and - 5 - and remove the seat forward/back adjuster motor - 1 - and bracket.
- Slide the seat rail - 3 - and - 4 - back and forth until the screw is accessible.
- Remove the screws and the seat rail.
- Replace the lower seat pan frame with seat forward/back adjustment motor. Refer to => [ Upper Seat Frame ] Upper Seat Frame.
Removing a faulty control module (J136) / (J521).
• Follow all safety precautions when working on pyrotechnic components. Refer to => [ Restraint System Components ] Description and Operation.
• Before handling pyrotechnical components (for example, disconnecting the connector), the person handling them must "discharge static electricity". For example, by briefly touching the door striker pin.
- Switch the ignition on.
- Disconnect the battery Ground (GND) cable with the ignition switched on.
- Disconnect the electrical connector on the seat forward/back adjustment motor.
- Connect the seat forward/back adjustment motor to an external power source and move the seat forward or back until the bolts - 1 - (quantity: 4) are visible.
- Remove the bolts - 1 -.
- Disconnect the electrical harness connectors at the coupling station; refer to => [ Harness Connectors, Disconnecting and Connecting ] Harness Connectors, Disconnecting and Connecting.
- Connect airbag adapter. Refer to => [ , Disconnecting and Connecting ] Airbag Adapter (VAS 6281), Disconnecting and Connecting.
- Raise the front seat with a 2nd technician and remove it from the vehicle.
- Attach the front seat to the fixture for seat repair (VAS 6136). Refer to => [ Installing the Front Seat on VAS 6136 ] Installing the Front Seat On VAS 6136.
- Replace control module (J136) / (J521). Refer to => [ Memory Seat/Steering Column Adjustment Control Module ] Memory Seat/Steering Column Adjustment Control Module.
Installing
• Follow all safety precautions when working on pyrotechnic components. Refer to => [ Restraint System Components ] Description and Operation.
• Before handling pyrotechnical components (for example, connecting electrical connector), the person handling them must "discharge static electricity". For example, by briefly touching the door striker pin.
Installation is reverse of removal, but note the following:
- Remove airbag adapter only after installing front seat. Refer to => [ , Disconnecting and Connecting ] Airbag Adapter (VAS 6281), Disconnecting and Connecting.
- Connect the connectors to the couplings of the coupling station in the floor. Refer to => [ Harness Connectors, Disconnecting and Connecting ] Harness Connectors, Disconnecting and Connecting.
• Make sure the connectors are installed all the way in and are secure.
Connect the battery with the ignition switched on. Pyrotechnic components could deploy after connecting the battery if they were not repaired correctly. Individuals must not be inside the vehicle when connecting the battery.
- Connect the battery GND cable with the ignition turned on.
• If the airbag indicator lamp (K75) indicates a fault after installation, the Diagnostic Trouble Code (DTC) memory must be checked, deleted and checked again using the vehicle diagnostic tester.