35d cranking but not starting

[wogboy_9000]

Originally Posted by blue dragon

You plugged in your basic OBDII scanner which has zero of the bmw specific fault codes. Either ask the dealer for the fault codes and report back, or get a copy of ISTA D and scan it yourself.


Without those codes, you are a blind man walking around in a pitch black night

100% agree. I really should have got the car towed home and run proper diagnostics. I had a call today and apparently it has been confirmed that it's a faulty CAS. The service advisor confirmed he'd incorrectly stated it was a 'comfort access' issue.

New unit has been ordered from Germany, so I'll report back in a few weeks when it arrives.

[ard]

Nobody in Oz that can help??


I would be a large sum of money that replacing the cas will not fix the issue that stopped a running car. My bet is fueling


Will they refund the money if it isnt the CAS?





Report back, will be interesting to hear.

[wogboy_9000]

I’ll report back when the module comes in.
I’m hoping the faulty CAS is experiencing intermittent communication issues with the DDE which might explain the initial stalling and the crank/no start condition that followed.

[13brian]

Dragon- am not being a troll, I truly mean this jocularly. I think pitch black does not affect blind man...
I do think it is a very good help suggestion.

[wogboy_9000]

Quick update. I finally have some more details.

So the faulty CAS is sending a constant signal to the DDE (which it should only be doing on start up). After a while of receiving a constant signal, the DDE effectively shuts down. Disconnecting the battery resets the DDE and you're then good to go again.

I'll be bringing the car home this evening so I'll run some diagnostics via ISTA+.

[ard]

what year is your car??





Im guessing S_START is the line they are saying?


I guess you could just mount a toggle swithc on that line, route it to under the dash..
Edit....cant drop in images, like the new bimmerfest software... I had grabbed a wire diagram showing the DDE inputs from the CAS. You should have that on ISTA. let us know if you need them

[wogboy_9000]

Thanks guys. Got it home and the cranking/no start condition started again. I plugged in the laptop with ISTA and there were about 50 errors. I cleared the slate clean and did a CAS/DDE alignment. It’s running fine now, so I’ll check the codes every few days and monitor.

The new CAS should be coming in the next few weeks (covered by my warranty), so it’ll be interesting to see if I experience these issues again prior to having it replaced.

[ard]

wow.


No sure what warranty you have (10 yr old car out of BMW warranty) but why replace the CAS if it is fine? Save the warranty $$$ for when it is needed.....

[wogboy_9000]

It’s a dealer used car warranty. I believe the underlying issue is that the CAS is constantly trying to communicate with the DDE. The dealer logged a case with BMW and they confirmed it shouldn’t be sending a constant signal. I’ll report back after continued code checking and report back.

In other good news, I reset my auto tailgate via ISTA and it’s finally working correctly!

[wogboy_9000]

Quick Update - I've been driving the car over the last few weeks and it has been fine, except for when I went on a longer drive and it died while driving and wouldn't start again.

I had my laptop on me so fired it up, connected ISTA, cleared the codes and did a CAS-DDE alignment (unsure if this was necessary but I did it anyway). It fired right back up without an issue.

I've attached screenshots of the errors - basically all CAS and DDE communication issues (I struck out the unrelated errors relating to my reverse camera, climate control and trailer).

New CAS went in yesterday so we'll see if it stops again.