Bosch 055 ECU pin out

[jpr210]

Hi, Anybody familiar with the pin-out of the Bosch 055 (euro M635csi) pin-out? looking to make a loom to shoot for a stand-alone ECU.

Thanks

Jpr

[woody6]

I'm looking for my old notes. I mapped out everything to install a Haltech E6X EFI unit in my 635, which could be done using most of the stock sensors. That was before I owned the M635, so I may or may not have ECU information for the M635. I would suspect, however, that they are very similar, if not identical. The reason being was that my research led me to believe that the Motronic computer (of any version) was the same across multiple makes of cars, only the chip was different. I will see what I can find this evening.

[woody6]

One more interesting data point. Steve Haygood asked me to plug the ECU from his U.S. Spec M5 (S38) into my M635 and see if it would run. I suspected it might not, after all his ECU was expecting an O2 sensor at the very least, something my euro car does not have. To my surprise, the car started and idled perfectly. I can't promise the pinout is the same as the 635, but I now suspect that it is.

[jpr210]

Thanks Woody, I suspect you are right. It would make sense that they are the same with only the tuning chip changed.

Thanks

Jpr

[BMW Performance]

[jpr210]

Thanks, Where would the injector output for 5&6 be in this scheme?

Jpr

[BMW Performance]

14 and 15 are 1-3 and 4-6

[jpr210]

there should be 3 spots that handle 2 cylinders each? I dont think that they do 3 cylinders in semi sequential injection.

[BMW Performance]

The pinout above came from online. It is a 1.0 and I did not catch it was an M3 not M6. 14 and 15 is correct for 3 injectors each.

[jpr210]

Great!!. Thanks

Jpr

[rlkrlk]

One more interesting data point. Steve Haygood asked me to plug the ECU from his U.S. Spec M5 (S38) into my M635 and see if it would run. I suspected it might not, after all his ECU was expecting an O2 sensor at the very least, something my euro car does not have. To my surprise, the car started and idled perfectly. I can't promise the pinout is the same as the 635, but I now suspect that it is.

I started the M635 with the AFM and plenum off (and sprayed carb cleaner thru the TBs under throttle). I'm pretty sure there's a default open loop circuit in the case that an O2 sensor signal is not detected.

Cheers,

Ray

p.s. The throttle response was pretty bad under the above scenario ;-)

[woody6]

there should be 3 spots that handle 2 cylinders each? I dont think that they do 3 cylinders in semi sequential injection.

My research showed that although there were two connections for injectors, they are all fired in 'batch' mode (all 6 at the same time).

[abdoul]

One more interesting data point. Steve Haygood asked me to plug the ECU from his U.S. Spec M5 (S38) into my M635 and see if it would run. I suspected it might not, after all his ECU was expecting an O2 sensor at the very least, something my euro car does not have. To my surprise, the car started and idled perfectly. I can't promise the pinout is the same as the 635, but I now suspect that it is.

... so with some luck. I might be OK? I have a 1985 M635csi but lost the ECU from a baodyshop (long story). I can't find a used or affordable ECU.. Will I be OK with the s38? Did you do any driving with it?

- - - Updated - - -

Alternatively. Can anyone help me source an ECU for a 1985 M635csi?

[rlkrlk]

... so with some luck. I might be OK? I have a 1985 M635csi but lost the ECU from a baodyshop (long story). I can't find a used or affordable ECU.. Will I be OK with the s38? Did you do any driving with it?

- - - Updated - - -

Alternatively. Can anyone help me source an ECU for a 1985 M635csi?

You might want to ask on the S38/M88 Google group. I think this link will get you there (and then register) https://groups.google.com/g/s38-m88

Cheers,

[woody6]

... so with some luck. I might be OK? I have a 1985 M635csi but lost the ECU from a baodyshop (long story). I can't find a used or affordable ECU.. Will I be OK with the s38? Did you do any driving with it?

- - - Updated - - -

Alternatively. Can anyone help me source an ECU for a 1985 M635csi?

Sorry, I didn't drive the M635 with the S38 ECU, as we were only trying to verify the S38 ECU was functional. If you can't find an M635 ecu, maybe you can find an M635 chip from someone that has upgraded. I have heard that the ECU's of the same Motronic version are the same, even across manifacturers. Maybe someone more knowledgeable, or someone who has tried this, can say for sure. Best of luck.

[Cjarvis]

I found this to be accurate when I installed a wideband o2 on an M88: https://www.bimmerforums.com/forum/a...1&d=1374092908 .
I tapped pins 2,3,7,16,21,35 with results as expected based on the diagram. Also found that those pins mapped correctly on an M106. So 2 for 2 on M30 based motors.