This bulletin applies only to BMW vehicles produced from 8-31-2009 to 2-25-2010, such as the BMW 328i X-Drive, equipped with SA 494 (front seat heating) and SA 534 (integrated automatic air conditioning).
The front seat heating sporadically activates on its own. The cause may be defective plug-in contacts in the wiring between the SZM (center console switch center) and the IHKA (integrated automatic air conditioning) control panel.
Perform diagnostics using ISTA for any fault codes that may pertain to the seat heating function.
1. Remove the IHKA control panel.
2. Remove the SZM.
3. Check the ribbon cable harness that comes from the SZM and plugs into the IHKA control panel for loose or damaged contacts.
4. If the cable harness is damaged, replace the SZM using the repair kit P/N 61 31 9 120 026.
5. If the cable harness is not damaged, continue troubleshooting.