Memory Seat Adjustment

Fault code 0668

Vehicle voltage, terminal 30

Diagnostic conditions
- Engine on
- Battery voltage OK (11.4 to 14.5 V)
- Internal function test on driver's memory seat adjustment control unit
- Engine speed > 2,000 rpm

Possible causes of fault
- Below lower limit (vehicle battery voltage is too low at less than 10.0 V)
- Above upper limit (vehicle battery voltage is too high at more than 16.0 V)

Affected pins
Memory seat adjustment control unit, driver's: Connector G
- Pin 1 'terminal 30 (voltage supply)'
- Pin 2 'terminal 31 (ground supply line for ground pin 31)'

Diagnosis/troubleshooting

WARNING: Danger of injury from limbs being trapped or severed.

NOTE: To gain access to the driver's memory seat adjustment control unit, tilt the driver's seat back.

NOTE:
Visual inspection: In the next troubleshooting section, first check that the affected pins on the driver's memory seat adjustment control unit plug connection are not damaged or corroded. The wiring and plugs of the affected components must also be checked for external damage and correct contact. Repair damaged or corroded pins if possible, otherwise replace affected pins. Repair or replace damaged wires.

NOTE:
Sporadic faults: In the event of sporadic faults, wiring points attached to moving parts on and in the vehicle must be checked systematically. Various statuses that can cause faults must be simulated with the help of the wiring diagram.

NOTE:
Battery voltage: A battery voltage of between 11.4 and 14.5 V is required for the following troubleshooting procedure. This must be checked and provided, if necessary. On the vehicle electrical system, the voltage to the fuse (input side) must be guaranteed.

NOTE: In the wiring harness from the driver's memory seat adjustment control unit to the fuse box at the left of the dashboard and to the body ground point, there is a disconnection point which must be included in the checks.