[herx]

Thanks Jason

The car doesn't run (apart from the misfires, has no throttle either, not sure if the two are linked) - if I remove my unit and get it to you would that work?

Just to clarify also, I am confident there has been no water ingress that's why I am stumped why it went bust? In your experience, do ECUs just die out of the blue?

 

[herx]

It has a "Prod. Date 2008-08-20"
E81
Manual

My garage mechanic took it out the car :

Weirdly enough the VIN is not visible (no it's not me that removed it before posting it). I suspect now that the previous owner(s) replaced it at some point in the past..

Symptom is Injector #1 does not get a signal from the ECU. The electrician has tested for continuity between the cable of the injector and the ECU and found no issue.

 

[herx]

Winchester

 

[herx]

Thanks for that
Unfortunately the car is with my mechanic 30 mins away from me and I already had the ECU in my hands so could not waste more time going back getting the CAS and key as well and have sent the ECU for diagnosis/repair elsewhere

 

[herx]

PM'ing you now

 

[herx]

https://www.ecutesting.com/

 

[herx]

Update / plot twist

Got the ECU tested with

https://www.ecutechnologies.co.uk/

(sorry Jason, it was half price) and it turns out there is no fault. I am running out of ideas now as to why it misfires... Will update once I get anywhere

 

[herx]

So you are saying there are no rigs that can test an ECU electronically i.e. MOSFETs outputing what they are supposed to output. A quick google search reveals the opposite

 

[herx]

Did you send them your Cas unit and key ?

No.

I am not saying you don't know your job, just to state the obvious in case I have been misunderstood. All I am saying is I prefer to "waste" 1/10th at the testing fee of these guys instead of the refurbished unit from you. Because it doesn't make sense for me to spend half of the value of the car if I were to scrap at £1k for a potential gain of maybe tops another £1k if I sold at £2k fully fixed. If I had a car worth the trouble, I would recover it to you but it's not the case I am afraid.

 

[herx]

If the above is seen as "crapping" then ok. "Help" is more than I am willing to spent on and has a price tag.

 

[herx]

So what did they charge you to test the ecu on there "rig" with the ecus ignition immobiliser being locked ???

I did not get charged, as they did not find a fault. I only spent postage to them, return postage covered by them.

 

[herx]

(I do not mind putting my VIN in the public domain)

One final update in case this thread proves helpful for anyone reading in the future having similar symptoms, although I do not have a definitive answer yet. I have strong evidence* though to suggest that the ECU after all is fine, hence I will not be updating this any longer, but may create a new topic for the ongoing issue.

*ISTA reports "ECU responding properly" plus using a bulb on all 4 injectors, now the bulb is flashing so they are receiving the pulse signal (don't have an oscilloscope I am afraid).

My garage (non-BMW specialist, just "plain" independent) threw in the towel. Hence, decided to recover the car back home and have a go (yet again) myself.

The video that motivated me was

The only "slight" difference is the fact that my ECU is *not* water damaged but I have been having the exact same symptoms (albeit now it cranks but does not start anymore). I have only been using INPA on my laptop because I had never managed to get ISTA working till now. I just changed the connection settings in ISTA and it communicated with the car fine after all.

The only relevant fault code I now got on ISTA was about injector #2. ISTA is so much more powerful than INPA that I am banging my head for not insisting in getting it to work any earlier. I tested the resistance across the two pins of both injectors #1 and #2 and it checked out (200kOhm give or take) fine (with the caveat, that this does not rule out still a faulty injector 100%).

The second and last step suggested by ISTA was the following which will be my next course of action in due course:

Since clearing the fault codes and trying to start the car several times, I have yet to get the injector fault (or anything else for that matter) back. The rest of my faults are irrelevant so ignoring them for now.

The other fault that is ongoing but is not throwing a fault code is I have no throttle. Again, using ISTA I confirmed (having watched how from the youtube video above) that the accelerator pedal position sensor is working fine. I haven't tested the throttle body yet.

TLDR: Still undiagnosed, but ECU is in the clear.