Step M7

Checking the AT-switch in the driver's door locking assembly.


NOTE: In some markets, operation by door key may be disabled.





- Ignition off.
- Disconnect central locking relay (item D/G).




- Connect an ohmmeter between item AT and item 31 on the central locking relay base.
The ohmmeter should read infinity.




- Maneuver the door lock 20 ° in one direction.
- Then maneuver the door lock 20 ° in the other direction.
The ohmmeter should show approx. 0 ohm in both cases.


NOTE: The AT-switch ground signal must appear before the central locking is maneuvered, i.e. a ground signal is obtained when it is turned approx. 20 °. This ground signal must remain until the central locking is maneuvered, which occurs when turned approx. 40 °.


If all readings are correct:
- Continue with step M8. Step M8

If there is some deviation:
There is a fault on the AT-switch in the driver's door lock assembly, or else a break in the signal lead or the ground lead to the AT-switch.
Alternatively the central lock may be maneuvered until the door key turns through 20 °.
- Rectify the fault or renew the AT-switch, or leads.
Replace the alarm control module.
Replace the central locking relay.