Seats: Testing and Inspection

Fault-tracing hints

Study the particular circuit wiring diagram and familiarize yourself with its operations.

1 Check that fuse 25 (driver seat) and fuse 26 (passenger seat) have not blown.

2 Check that there is a supple voltage to fuse 25 and fuse 26.

Connect the test lamp (part no.86 11 857) between both pins on the sensor connector. The test lamp should come on.

If the lamp lights, continue with point 2.

If the test lamp fails to light, continue the fault diagnosis using wiring diagram.

3 Check that the voltage is supplied to the particular switch, partly when the front door is open and partly when the ignition switch is in the ON position and the relevant front door is closed.

4 Check that the four motors are supplied with voltage when the switches are activated. Unfasten the connectors to the particular motors.

Connect a voltmeter between the two pins on the sensor connector. Activate the respective switch in both directions and the voltmeter should display +12v or -12v.





Note: The current M95 introduced a 10 pole connector, H1O-27, that simplifies fault diagnosis regarding the motor voltage supply.

Unfasten connectors H10-27.

None of the four motors operate:

Connect the test lamp between pin 10 of the sensor connector and a definite grounding point.

Connect the test lamp between pin 9 and 10 of the sensor connector.

The test lamp should light in tests with open front door and with closed front door with the ignition switch in the ON position.

If the lamp comes ON, change the switch. If the lamp fails to came ON, check the wiring harness.

Some of the four motors operate:

Connect a Ohmmeter onto the following Pins.

pin 1 and pin 2
pin 3 and pin 4
pin 5 and pin 6
pin 7 and pin 8.

The ohmmeter should normally display OL and 1W when the relevant switch is activated in both directions.

If the ohm-meter displays a fault, check the cables and connections. If there is no fault, change the switch.

5 Inspect the connectors, wiring and ground connection.