copied from Bentley publishers (who suggest getting the s85 as the DME is similar, also this coupled with the basic e9x chaissis manual should be sufficient)
Posted: Feb 26, 2009 11:03 AM in response to: DCbmwTech
Great car. Drove on at O'fest in NY this fall.
Currently, we do not have plans to cover the 4th generation M3 in our E90/91/92/93 service manual. Your M3 uses the MSS60 Engine Control System, very similar to the MSS65 used on the S85 engine (M5, M6)
I'd suggest you buy a one day subscription to www.bmwtechinfo.com
and download the training (be sure to get stuff on MSS65, the MSS60 is a little weak), repair, and any bulletins, etc. I know a lot of work, but it is all I can think of.
Here's an exaple of ths stuff you find:
Ion Current Combustion Monitoring
In the S65, the ion current electronic system is integrated into each ignition coil and
the ion current control devices are not required.
For the purposes of smoothing the voltage and electromagnetic compatibility, an
"ignition suppression capacitor" is installed in the wiring harness of each cylinder bank
(in the S85 this is in the ion current control device). This is electrically connected using
terminal 87 and the vehicle earth.
If the ignition suppression capacitor is defective, this can lead to faults in the communications
and/or audio electronics when the engine is running.
For design reasons, the firing order 1-5-4-8-7-2-6-3 is used in the S65, instead of the
firing order 1-5-4-8-6-3-7-2 more commonly employed in BMW V8 engines.
4th Generation M3 Service Information
MSS60 Engine Control System"