Motronic 2.5 vs. 2.7

That does sound odd - 2.5 was on the 89 to mid-90, easily identified by the single throttle position sensor as opposed to the 2.7 which has two. Maybe the motor was replaced with an older unit at some point? The 2.7 has the advantage of allowing you to pull error codes in addition to improved software and mappings.

 

Oh, I've been meaning to ask. How does one pull error codes from a 2.7? I've got a 1995 F355 and my business partner has a 1995 348. I've got an OBDII code reader, but am guessing that it's not going to do anything for me on an OBD I car.

 

Courtesy of Ernie and No Doubt:
http://www.my348.com/348.html#ECUcodes

 

There isn't anything worst about the 2.5 vs. the 2.7 and pulling codes on the 2.7 is just as likely to give incorrect diagnosis. If you are really curious, you could get copies of the schematics and compare the differences. For example, the thermocouple module on the 2.5 just lights warnig bulbs on the instrument panel vs, the 2.7 also has a wire connected to the Motronic ecu probably to limit engine revs if the cats are overheating. Best advice: buy the car that you like and fix what breaks. FWIW

Jeff Pintler
89 348tb (2.5), 86tr, 99 360 3 pedal

 

Hi guys,

I was talking to my mechanic in regards of what I read in this discussion to tell the difference between a 2.5 or 2.7. I told him about the throtle position sensor (my 348ts has two). Is there any other way to see easily if it is a 2.7?. Do you have any pictures of a 2.5 vs 2.7 to compare?. Thanks!.

 

In addition to seeing two TPS-s, you can re-confirm that it is a 2.7 by looking at the ECU number:

2.5: Bosch 0 261 200 190

2.7: Bosch 0 261 200 457 (TB/TS) or 0 261 200 489 (Spider & Challenge) or 0 261 203 327 (superseded the 489)

There might have been other Bosch numbers for the 2.7 for certain markets/countries but, as far as I know, there was only one number, the "190", for the 2.5.

 

Thanks a lot!, Forgive me if my next question is stupid. It is a dignostic tool to get the number or is it visible from the outside?. My mechanic has a Leonardo and if I am nor wrong it is OBD2. Any OBD2 to OBD1 converter would work?. The 348 has OBD1, correct?

 

You just open one of the covers of the ECU compartment and you will see the Bosch number on the ECU on a yellow sticker. The 348 has "vintage" ECU-s, no OBD.