Engine Controls - DME M1.3 Sensitivity: Overview

91bmw11

Group 12
Engine-Electrical


Bulletin Number
12 06 89 (1878)


Woodcliff Lake, NJ
October 1991
Product Engineering


This Service Information bulletin supersedes S.I. 12 06 89 (1878) dated May 1989 which should be removed from your S.I. binder and discarded. It specifies a new repair procedure for Service Action 20 and provides information on how to deal with previously modified cars that require Motronic control unit encoding.

SUBJECT: DME M1.3 Sensitivity

MODELS: MY 1989 E30/E34 with M20 Engine (produced from 6/88 through 5/89)


Complaint: 1) "CHECK ENGINE" light illuminated and possibly poor engine performance. Other symptoms may include:

- prolonged starting time
- incorrect and undefined error codes such as "DME control unit selftest negative" or "programming faulty".

2) A previously modified vehicle requires the installation of a new Motronic control unit which has to be encoded first. The encoding cannot be performed because pin 18 is removed from the diagnostic connector.