Seat Heater - Headlights Dim/Idle Fluctuations
Group 61General Electrical Systems
Bulletin Number
61 02 01
Woodcliff Lake, NJ
October 2001
Service Engineering
This Service Information bulletin supersedes S.I. 61 02 01 dated July 2001.
SUBJECT
Headlight Brightness and Idle Speed Fluctuations with Seat Heating On
MODEL
E46, 3 Series produced from 09/99 up to 07/01
SITUATION
Customer may complain of headlights brightness and idle speed fluctuations when both seat heating elements are turned ON.
CAUSE
Voltage drops induced by the load response function of the alternator, when both seat heaters are turned ON.
CORRECTION
On a customer complaint basis only, and after verifying the complaint, replace the Center Console Switch Module (SZM) with the improved part number 61 31 6 914 744 (software version SW 03).
PROCEDURE
To verify the complaint: with the engine running, switch on both seat heaters (with maximum heating level) and turn on the exterior lights. After a short period of time (when maximum seat temperature is reached), the seat heating system will enter the regulation mode and the fault can be duplicated.
For the SZM module replacing procedure, refer to Repair Instruction RA 5116... ("Removing and installing carrier in storage tray") which can be found in BMW Technical Information System (TIS).
PARTS INFORMATION
Part Number Description Quantity
61 31 6 914 744 SZM module 1
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.