Difference between BOSCH DME ML3.1 and ML3.2
 

Hello,

I know that there are some specialists regarding Bosch Motronics on this board.
So, can somebody tell me the difference between a Motronic (resp.DME) ML3.1 and a ML3.2 (or 3.3) ?

Are there good infos somewhere in the web regarding the history of BOSCH motronics ?

My guess is that the letters only say something about the principle (L, LH, ML, M...) and the numbers are just revisions.

Somebody out there who can answer this ?


Thanks in advance,
Marco

Marco:

FR Wilks probably knows more about Bosch DME's than anyone else I know. You might try contacting him.

http://frwilk.com/944dme/

Tim

D-Jetronic, the D is short for Druck, the german word for pressure. Manifold pressure is measured to indicate engine load. L-Jetronic, the L is short for Luft, the german word for air. Air flow into the engine is measured with a movable vane (AFM). LH-Jetronic, the H is short for Heiss, the German word for hot. Air flow is measured with a hot wire. :) K-Jetronic, the K is short for Kontinuerlich, the German word for continuous. Air flow is measured with a circular plate. KE-Jetronic is mechanical control with electronic modulation of the fuel mixture. ML is motronic with electronic control of everything and using an AFM (barndoor) for air measurement, etc. etc. Probst's book on fuel injection is good source for more info.

Nobody else on this issue ?

What do the numbers mean ?

Greetings,
Marco

Shoot the Motronics expert an e-mail, Todd Knighton.

knighton@protomotive.com

He'd be able to answer all your Motronics questions ;)

The early Motronics as used on the Porsche 3.2 and BMWs were basically DME 1.X,
(35 pins). The DMEs as used on the 964 with on-borard-diagnostics was DME 2.X (55 pins),
and on early 993s. The later 993 DME 3.1 (88 pins) had a mask ROM versus an EPROM.
The 993 DME 3.2 (88 pins) used a flash memory (EEPROM) and an immobilizer code (alarm lockout).
The final 993 with OBDII diagnostics used DME 5.X (88 pins) with flash memory which can be
reprogrammed externally.

The key is the Bosch number used (0 261 XXX YYY). The XXX denotes the DME type.

Check out this web site (www.systemsc.com) on the Parts page for more info.

Note: DME and Motronic are synonymous terms.

Speaking about a Carrera 3,2.
The BOSCH references the DME as a ML3.1.
(But I have also seen some references as M1.0 and so)

What is a ML3.1 ?

Greetings,
Marco

"Speaking about a Carrera 3,2.
The BOSCH references the DME as a ML3.1."

Buy some Porsche manuals & then read the Porsche manuals!

The 993 manual (WKD 498 621) states the 993 uses DME 2.10.1 (page 2-1).

The ONLY changes for the 911 3.2 DME from '84-'89 were EPROM changes;

1. early - 16K
2. '87 - 32K
3. '88 - '89 - 64K

All 911 3.2 DMEs function the SAME and are therefore interchangeable.

Go to a BOSCH webpage and read the electronic parts catalogue !!!

BOSCH is referencing to it as ML3.1 !

I have a Porsche manual myself and there is no other information in there (not in Bentley, Porsche Reparaturleitafden or elsewhere)


Is it not allowed to ask questions, buddy ?

Greetings,
Marco

Your answers are here on this thread!