VSS OBDII wiring questions.

[nando]

the OBDII dme's should be well known by now, no?

[dmjensen]

Finding that byte is the fun part ;-)

Oh you turd. Well, if your saying it doesn't need to be an accurate signal just a signal of movement to get rid of the check light then I think that pin # 20 x20 will be the ticket.

[dmjensen]

I was was wrong, 20 x20 goes to pin 36 x6000 and according to the pin outs on that connector its engine speed (rpm)

[evandael]

can anyone comment on why the ETM says the DME VSS input is on pin 171?



the x6000 only has 88 pins.. but does it have 88 inputs as well, yielding 176 total 'connections', as seen in this image? (note, i cut off the bottom of the page, this is page 1210.20-c)

[dmjensen]

not sure what you found there but your right that is strange, but I just flipped through the etm fast and couldn't find any pins going to the DME (besides the pin out above) that go higher then 88....

328junkie, I found that #9 in x20 leads to pin 15 x6000 (right rear speed sig) and to pin 15 x1171 also rear speed signal. Is that the pin you speak of? because that would explain why you need to convert the signal.

[evandael]

unless it is internally jumpered, i cannot figure it out.


SPECULATION ALERT

it's possible, that given other people's success with the swap, that with x6031p3, 'TI measurement fuel signal' is actually just a different name for VSS output from the e36 cluster.

/speculation

that still doesn't fix the difference in frequency noted between the e30 VSS and the req'd e36 VSS, but maybe one could hook up a diagnostics system and see if there is a difference between using the e30 VSS from the diff sensor and using a conditioned ABS signal.


you found x20p9 which is the wheel speed signal that i believe is used in the ASC system. a signal from an ABS sensor would need to be conditioned, however, using x20p9 would likely not solve your VSS problems.

x20p20 is an RPM output, not VSS input. not sure why that is being used.

[nando]

unless it is internally jumpered, i cannot figure it out.


SPECULATION ALERT

it's possible, that given other people's success with the swap, that with x6031p3, 'TI measurement fuel signal' is actually just a different name for VSS output from the e36 cluster.

/speculation

that still doesn't fix the difference in frequency noted between the e30 VSS and the req'd e36 VSS, but maybe one could hook up a diagnostics system and see if there is a difference between using the e30 VSS from the diff sensor and using a conditioned ABS signal.


you found x20p9 which is the wheel speed signal that i believe is used in the ASC system. a signal from an ABS sensor would need to be conditioned, however, using x20p9 would likely not solve your VSS problems.

x20p20 is an RPM output, not VSS input. not sure why that is being used.

no. the TI signal is a conditioned fuel injector pulsewidth that the cluster/OBC turns into an MPG reading.

[evandael]

^ okay, and since there is no black/white VSS wire in the x6031 (both in dmjensen's image and in the ETMs).. it remains a mystery.

[dmjensen]

Its no mystery, its in the x20 connector. The e36 dme just uses a different signal apparently.

[evandael]

so is it x20 pin 9, or x6031 pin 3?


have you wired it up?

[Gooch]

Pin 3 on the x6031.

[dmjensen]

Pin 3 on x6031 is a fuel compsumption signal, only reason it works is because its giving the computer a signal that isnt 0 voltage. I'll try both pin 9 x20 and pin 3 x6031. I will report my findings after hooking up inpa while driving around to look for a semi accurate speed signal.

[mammoth_e30]

Any report on this? I still have the P0500 code coming up. I have read and reread the e36 obd2 ETM and x6031p3 has to be the VSS/speed signal. Why this works for some people and not others is a complete mystery to me.

Pin x20p9 is ABS/ASC from what I have seen, I would make an assumption this won't fix our problem but if by chance it works....

My smog is due this month and I have not been able to get to the BAR referee because of this damn check engine light so I am up a creek without a paddle and will either pay out the ass for smog or find a way to register my car out of state.

[chris_rai]

me too i got a code :

VSS signal not OK / ready, hitting the rev limiter a little earlier

fuel trims too, looks very innacurate

[luckysnafu]

I have pin 9 of the X20 (white/gray with yellow dashes) connected to pin 14 of the C101 (black/white) and I don't get any codes or problems with rev limiting. I have an early 96 m52 engine with OBDII still wired up.

I can verify via the Android Torque app that my ecu is receiving the speed signal. From another thread (http://www.r3vlimited.com/board/showthread.php?t=264748) we determined the following:

48 pulses for e30 and 9 for the e36 equals a ratio of 5.33333. If you enter this into the Torque app speed multiplier you will get your actual speed. The e36 ecu doesn't care what signal it's getting, as long as it gets one, as others above have stated.

Hope this helps clear things up.