Members Page/Sascha/Schnell Ethritysix/EC Uissues

The page title is "ECU issues"

but it's almost certain now, that the ECU is behaving reproducibly (same as a known good ECU)

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: http://vems.hu/vemstune/sharingcenter/reports.php?cmd=view&key=5wb985

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: http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FInputTriggerHardWare

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)

SOLVED: I later found that home-conversion of trigger most likely did not succeed because there was apparently a short to GND
- in the line coming from the voltage regulator (+5V or +5.5V ?) to the ignition chip (i259 ? Or some other ? Which line exactly ? Some lbus data or address or chip select line ?) which was causing my issues. I was unable to find where the short was and the ECU was returned to VEMS USA

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

type : ... Injector Dynamics ID1000 (EV14 base)
size : ... 1000 cc/min

Can you check and detail the flyback path ? Specifically what should I look for? I'm not too familiar/never had to do this before.
- also measure all IAC and inj outputs in use with DVM: low voltage flyback is recommended for IAC outputs; If DVM diode mode measures <1.9V between output and EC36/23 as a base, that is good for IAC. Else (perhaps not requested any injout with low voltage flyback), easy to use BY399 diode (or STPS340U SMB or ER2J or ES2J or SS24 SMB diode, or even 1n4007 for max 1A load), cathode on EC36/23 (some hides it in the boot at the connector).
Stock E36 factory BMW wiring harness with Motronic (55?) plug cut off and various sensor/outputs removed from harness (NB O2, SAI, etc)
IAC originally wired to INJ 7+8 (Dual solenoid)
ID1000 Injectors

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.

Symptoms:

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.

it is also possible, that the 1.5ke30 transient diode inside the ECU, or the big 4.7uF 63V foil capacitor at the flyback rail got damaged somehow (or broke down, or sg).
- Is there a way to test if it's damaged?

Tests:

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?

yes, definitely lack of flyback, obviously when used on ignout, use diode outside, very easy, do that first
Motor likes to stall often and run at very low RPM when cold (even though DC is higher).

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:

This log is driving with the IAC connected to INJ output as it has been for 4+ years, and at some point towards the end of the log I disconnected the IAC @ the connector and drove about 2-3 min more to final destination for test w/ no map/tune changes at all: http://www.vems.hu/files/MembersPage/Sascha/SCHNELL-E36/v3.3_u006414-2017.06.19-16.52.18.vemslog

This log is a short drive with IAC still disconnected, but with some VE changes: http://www.vems.hu/files/MembersPage/Sascha/SCHNELL-E36/v3.3_u006414-2017.06.19-19.34.19.vemslog

This log is a long drive with IAC put on IGN output, and tuning/VE changes being done throughout: http://www.vems.hu/files/MembersPage/Sascha/SCHNELL-E36/v3.3_u006414-2017.06.19-21.39.05.vemslog

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: http://www.vems.hu/files/MembersPage/Sascha/SCHNELL-E36/v3.3_u006804-2017.06.19-20.54.55-DAVE_E30.vemslog

Suggestions on settings

There are BMW IAC valves which have spring-loaded default position for a limp-home mode at ~30-40% opening. Looking at your first log above it seems to me that a +10kPa jump in MAP is apparent when the IAC value reaches 0. I think this is the point where the ECU disables energizing the valve, and the valve is jumping from the energized closed (0%) position to the spring-loaded default position. You can check this behavior by manually forcing IAC positions and plugging of the valve in-between. If there's no change to idle RPM you've got the IAC valve default position equals to its spring setting. After that, set this position as the minimum in IAC settings and force close, that way you can avoid such jumps in MAP. Hope this solves your problem! (GergelyLezsak)
- Thanks for the suggestion, I will try that for sure. But unfortunately at this point the issue is not with the IAC closed setting, since this happened when I don't force close the IAC. This happens all the time when the IAC is being powered down by the ECU. And during that time when it is powering down the car physically decelerates, something I don't have an issue with on any other car with my settings as per usual (forcing completed closed the IAC @ 22%). But maybe I will be able to at least avoid some annoyance for now. For what it's worth, yesterday I swapped out my ECU for a friends ECU and the problem still exists on my car. So the issue is not with the ECU, but rather with the car/harness/IAC?

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% ;

perhaps just 5..10% for other IAC ?). A low voltage flyback (eg. BY399 or even 1n4007 if only have that) diode across the solenoid (cathode on the constant +12V pin) helps to reduce electric consumption and electromagnetic noise
Tried that ? Results in too much air and raised idle ?
- Tried another IAC valve tests seem to show that similar reaction is made. At this point I am unsure what is causing my running issue. You are correct in thinking that forcing the IAC to close position helps (keeps MAP stable), but the issue only truly goes away for me if I cheat the IAC force close to NEVER go to 0 DUTY which the ECU always seems to do regardless of the settings to power off or not. I have to cheat by putting the power off time to 255s, that way it gives enough time for it to never close. So far that has helped me avoid most of my issues with the IAC situation. I still do not understand how I can have this issue but friends car with exact same setup (same IAC, same motor, almost identical plumbing of IAC, same IAC connection to ECU, etc.) does not have this issue at all.