BMW alternator operation, voltage output, and battery charging are monitored by the DME module.
In this guide, we take a look at the functions of the center console switch cluster (SZM) used to adjust the steering column and how to diagnose the SZM module with an OBD-II diagnostic scanner.
What is BMW SZM switch?
Steering column adjustment is on the left-hand side of the steering column.
SZM is the BMW term for Centre Console Switch Cluster. When the driver adjusts the steering column signal is sent to the steering column switch cluster (SZL) which control the steering column motor.
If your BMW SZM module fails you may notice that you can no longer adjust the steering wheel.
Diagnose BMW SZM switch problems
If you are experiencing problems a good starting point is to read fault codes from the SZM module.
What you will need
For this step, you will need a diagnostic scanner that is capable of reading, clearing codes from BMW SZM module.
- Plugin the OBD-II scanner into the diagnostic port under the dashboard.
- Turn on the ignition, don't start the engine.
- Turn on the scanner and select your BMW chassis. Next, Select Control Units menu.
- Select the SZM Module.
- Once you enter the SZM module, you will be able to do the following.
- Read Codes from SZM Module
- Clear Codes from SZM Module
- Perform Adaptations, Activations, Tests
If any code is showing PRESENT status the problem needs to be fixed before the code can be cleared.
Note that the SZM is connected to the IHR/IHKR/IHKA control unit via a 14-pin connector.
When purchasing a BMW scanner, verify that the supports your BMW model and year.