Immediately following a cold start, if the heated steering wheel is switched on in addition to other electrical consumers (i.e., heated seats, rear defroster, etc.), it may switch off after 5-10 seconds of operation. This is an intermittent situation. Cycling the key will typically restore function.More repair cases about BMW,please check here:BMW Trouble Repair
CAUSE
For the first few seconds after start-up, voltage levels may dip momentarily when electrical consumers are switched on. If the supply voltage dips below the threshold for the heated steering wheel, it will be switched off.
This situation may be present even if the battery is properly charged and no charging system problems are present.
MODEL
E90, E91, E92, E93 (3 Series) produced from 9/2008 and equipped with the Heated Steering Wheel (SA 248)
E82, E88 (1 Series) produced from 9/2008 and equipped with the Heated Steering Wheel (SA 248)
CORRECTION
Replace the steering wheel electronics with an updated part.
PROCEDURE
1Remove the steering wheel airbag per Repair Instruction REP 32 34 020 (Standard steering wheel) or REP 32 34 030 (Sports steering wheel).
2Remove the multifunction buttons per Repair Instruction REP 61 31 229.
3Replace the steering wheel heating module as shown in the attachment SIB320109 Procedure.pdf.
NOTE: The routing of the wire harness for the steering wheel heating module varies from model to model. Take note of how the original part was routed, and ensure that the replacement parts are routed the same way.
PARTS INFORMATION
61 31 9 217 864 Steering wheel module – Base wheel 1 – If applicable
61 31 9 217 865 Steering wheel module – Sports wheel 1 – If applicable
For detail information about parts,you also can check them on BMW ETK parts.