Checking Drive Status, Seat
ZA Fault-tracing informationCondition
No diagnostic trouble codes (DTCs)
The fault is permanent.
Possible source
- Contact resistance in terminals.
- Open-circuit on wiring to motors 1, 3, or 4.
- Defective motor 1, 3 or 4.
- Defective drive gear.
- Defective drive cable.
Power seat with memory, additionally:
- Defective control module.
Fault symptom(s)
- Seat will not move forward/backward.
- Seat will not adjust for height.
- Fault-tracing begins at ZB.
ZB. Checking drive status, seat
ZB1 Conditions
This fault-tracing procedure assumes that there are no faults detected in the control panel.
Has fault-tracing been carried out on the control panel ?
Yes:
- Seat with memory: ZB2
- Seat without memory: ZB5
No:
- Carry out fault-tracing on the control panel in accordance with the Symptom Table. Symptom Table
ZB2 Check activation
- Ignition OFF.
Run the power seat adjustment forward/backward and for front edge/rear edge adjustment in both directions using the control buttons.
Are the seat adjustment functions for forward/backward and seat height front/rear edges operating correctly?
Yes:
- Fault not found
No:
- ZB3
ZB3 Checking the control module
- Ignition OFF.
- Remove seat from car.
- Connect adapter cables to the seat in accordance with Wiring Up Procedure. Wiring Up For Voltage Measurement
Connect a voltmeter between ground and the respective position in the black 14-pin connector C, for the function as listed below:
- C:1, seat adjustment forward
- C:2, seat adjustment backward
- C:3, seat rear edge vertical adjustment upward
- C:4, seat rear edge vertical adjustment downward
- C:5, seat front edge vertical adjustment upward
- C:6, seat front edge vertical adjustment downward
Activate the respective functions using the control buttons.
The voltmeter should read battery voltage when the function is activated.
If reading is OK:
- ZB5
If reading is incorrect:
- ZB4
ZB4 Replace component
Try a new control module.
Then continue with:
- ZB12
ZB5 Checking motor
- Ignition OFF.
- Cabling in accordance with Wiring Up Procedure. Wiring Up For Voltage Measurement
- Remove the motor being tested from the drive gear.
Activate the motor to be tested using the control buttons.
Is the motor working ?
Yes:
- ZB7
No:
- ZB6
ZB6 Replace component
Try a new motor.
Then continue with:
- ZB12
ZB7 Checking drive cable operation
- Ignition OFF.
- Cabling in accordance with Wiring Up Procedure. Wiring Up For Voltage Measurement
- Disconnect the drive cable from the drive gear.
- Reinstall drive cable on motor.
Activate the motor being tested with the control button for the seat.
Check the drive cable. The drive cable should turn.
If reading is OK:
- ZB9
If reading is incorrect:
- ZB8
ZB8 Replace component
Try a new drive cable according to
- HHG. Right cable to seat center motor
- HHH. Left cable to seat center motor
- HHI. Right cable to seat rear motor
- HHF. Right cable to seat front motor
Then continue with:
- ZB12
ZB9 Checking drive gear
- Ignition OFF.
Check the drive gear by adjusting the seat manually using the crank 340 6731.
Is the drive gear working ?
Yes:
- ZB11
No:
- ZB10
ZB10 Replace component
Try a new drive gear.
Then continue with:
- ZB12
ZB11 Checking drive cable length
- Ignition OFF.
Measure distance between sheath sleeve and cable end. The wire should stick out at least 10 mm (0.4 in.).
If reading is OK:
- Fault not found
If reading is incorrect:
- ZB8
ZB12 Verification
Hint: After carrying out the repair, check that the fault has been remedied as follows:
- Ignition OFF.
- Reinstall components, connectors etc.
Run the power seat adjustment forward/backward and for height adjustment front edge/rear edge in both directions using the control buttons.
Are the seat adjustment functions for forward/backward and seat height front/rear edges operating correctly?
Yes:
- Fault corrected
No:
- ZB13
ZB13 Fault-tracing information
The verification result shows that the fault persists.
Do you want to exit fault-tracing ?
Yes:
- Fault not corrected
No:
- ZB1