Defective O2 Sensor - Delay Function Embodied In ECM (IDC 1000/92-15)

DEFECTIVE O2 SENSOR - DELAY FUNCTION EMBODIED IN ECM

TECHNICAL SERVICE BULLETIN

RE-PROGRAMMING ENGINE CONTROL MODULE USING MoDiC RE-CODING DISK "RECODING DME M3.1 M50 VERSION 2.0"

Model(s): 1991-92 BMW 325i (E36), 525i (E34) with M50 Engine

Group: 15

Bulletin No.: IDC 1000/92-15

Date: June, 1992

SITUATION

System: MoDiC

Version: Recoding Engine Control Module M3.1 M50 Version 2.0

Control Module: M3.1 Engine Control Module, 6-cylinder M50

If a vehicle is found to have a defective oxygen sensor, his failure is possibly due to "thermal shock". Thermal shock may occur only under certain environmental conditions when a cold engine is started and moisture/condensation in the exhaust passes over the heated oxygen sensor causing a rapid cooling of the sensor's ceramic outer shell. This rapid cooling may cause the ceramic shell to shatter or crack.

SOLUTION

A brief delay function for the activation of the oxygen sensor or heater relay has been incorporated into the latest version engine control modules. For earlier vehicles, the engine control module may be updated with the oxygen sensor heater delay function using the MoDiC recoding disk "Re-coding DME M3.1 M50 Version 2.0".

Only engine control modules with the following Bosch Hardware Numbers are affected:

0 261 200 403

0 261 200 405

One copy of this diskette is being sent out to each dealer via the Automatic Tool Shipment Program.

Recoding DME M3.1 M50 Version 2.0' (for BMW MoDiC) P/N 01 51 9 786 621

REPROGRAMMING ENGINE CONTROL MODULE USING MoDiC RECODING DISK DECODING DME M3.1 M50 VERSION 2.0

• During recoding,

  - the ignition must not be switched off.

  - no other work may be carried out on the vehicle,

  - the MoDiC must not be disconnected.

• During data transfer, the idle speed control valve is activated and a clicking noise will be heard.

REPAIR PROCEDURE

1. Verify engine control module Bosch Hardware Number is 0 261 200 403 or 0 261 200 405 (only these Bosch Hardware Numbers are affected).
2. Read out fault memory and erase any fault codes stored.
3. Load re-coding program into the BMW MoDiC via the BMW Service Test (use the same secret number assigned to your dealership for previous MoDiC download disks).
4. Connect MoDiC to the diagnostic connector in the engine compartment.
5. Switch on the ignition.
6. Select "Recoding DME" from the main menu.
7. Confirm "DME M3.1 M150 Version 2.O" by pressing right arrow key.
   • If the engine control module has previously been recoded or does not require recoding, the following message will appear on the MoDiC display:
   • "Measure not applicable to this control module version."
   • If this message appears, exit recoding program by pressing the "up" arrow key to return to the main menu: no further action is required.
8. Enter vehicle's mileage and confirm by pressing the " " key.
9. Start automatic re-coding by pressing the " " key. The display will read "DME automatic recoding active, please wait". During the recoding process, a bar graph indicates the amount of data already transmitted; recoding process takes approximately one (1) minute.
10. If the recoding process is completed successfully, the display will read "DME recoding completed"; return to the main menu by pressing the "up" arrow key.
11. Switch off ignition.
12. Disconnect MoDiC from the diagnostic connector and re-install the diagnostic connector cap.
13. Wait at least 10 seconds prior to starting engine.