Fault Code 1902
Fault code 1902Motor for horizontal lumbar adjustment
Diagnostic conditions
- Ignition on
- Battery voltage OK (11.4 to 14.5 V)
- Internal function test on driver's memory seat adjustment control unit
Possible causes of fault
- No horizontal lumbar adjustment possible (Electrical fault in electric circuit)
- No horizontal lumbar adjustment possible (short circuit to B+)
- No horizontal lumbar adjustment possible (short circuit to ground)
- No horizontal lumbar adjustment possible (open circuit)
Affected pins
Memory seat adjustment control unit, driver's: Connector C
- Pin 1 'horizontal lumbar 1'
- Pin 2 'horizontal lumbar 2'
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 horizontal lumbar adjustment motor, there is a disconnection point which must be included in the checks.
