The page title is "ECU issues"

Historical: Old hunting after/during some home conversion of input-triggers

Not really sure what is going on here, but none of my IGN outputs are working...

The box is installed in my (M52 w/ HALL/HALL setup) E36 BMW, I had to convert the box from VR to Hall on the pri trigger, everything else seems to work just fine (P259, INJ, etc) but I cannot get any reaction from any of the IGN outputs no matter what I configure them as even in "test mode"

Any ideas?

Generic hint: first setup and test triggers independently from any outputs. Just the triggers, watching InputTrigger/TriggerLog

I've tried reloading and changing firmwares and nothing has helped.

12+ and GND, and EC36 pinouts have has been verified and tested ok... using an LED to test the outputs.

here is one of the cfg's:

so just to re-cap.. this is what I did to the board to switch from VR to HALL

is there something that I could have done here in the process like bridge trig1 that could have damaged something?? or by changing/removing a resistor?


I followed the V3.3 instructions from this page:

soldering JP2 & JP7 didn't work for me.. the pri trigger didn't work with that soldered, but started to work with it unsoldered

changed R30 to 2k4 (strong pullup).

removed R56 completely, soldered blob @ SJ2, removed blob @ SJ6

Measured the blob @ SJ2 and have 3.8V to GND with hall sensor unplugged and the trigger's (both pri/sec working wonderfully)

JUNE 2017:

Running issues - Injector characteristics are wonky when IAC is being controlled. This issue isn't apparent in other BMW's which I have done

Background info:

injectors: measured resistance = .... Ohm ? All measure within 0.2 ohm of each other - going from memory 13.6-8

I have been struggling with poor injector control since installing this box many years ago, also been struggling with odd/inconsistent IAC control but am unable to understand if it is the IAC control of due to Inj. control.


During light loads and under 80 kpa/constant throttle applications the car feels like it slows down and has a step in power.

Finally the other day I happened to be playing with IAC PID's so I was on the standard IAC page of VT. I happened to notice that the issue start and ends when the IAC starts to count down to 0, and once the IAC position reaches 0, the car bucks and seems like it gains about 20 hp and lurches forward.

Now that I've noticed it, I've been able to consistently recreate the issue and it is timed perfectly with IAC movement/shutdown.

Nice find ! Check that you have low voltage flyback for IAC outputs, and not for injoutputs used for injectors.


So far I have attempted disconnecting the IAC, this immediately resolved the driveability issues at light throttle (especially in parking lot driving).

I have since moved the IAC from INJ 7+8 to IGN outputs, unfortunately IAC control now is very, very poor and has limited range (seems like IGN output is not strong enough or maybe lack of fly back is the cause?

Example. on INJ output, DC table was between 70-30% but on IGN outputs DC table is at the min 80-100% and this doesn't give enough adjustability.

Logs are as follows:

As an extra note, I happened to be at a friends house that has M52 swapped E30 w/ VEMS that I installed/tuned, this car along with others do not exhibit this issue at all! So here is a small log example (was out tuning the AC/IAC input:

Suggestions on settings

Swapped in known working ECU - problem still exists

Yesterday to speed up diag. I swapped in my friends ECU from his E30 w/ M52, IAC is setup exactly the same (log is linked above). I loaded my CFG and moved IAC back to INJ outputs on my harness.

Problem was still there. So it shows that at least ECU is not at fault at this point. Problem must be with the harness or possibly a failing IAC. Will try another IAC valve in the next few days and report back.

Difference between the E30 and my car is E30 has a brand new wiring harness I made for it and not stock harness. But I have to wonder if people with M5x PnP? boxes are having this issue or not?

What if the IAC is configured to not power down completely ? Eg. in Audi AAN (and other apps with similar, usually somewhat fat IAC) it is very common to set nonzero IAC min duty (eg. min 24% ;