Weird ACC errors

stormlv · 05-16-2015, 10:30 AM

I started getting some weird errors from the ACC.

In the dash I get the "Front Collision Warning is inactive" (or something of the sort).

If I use ISTA and check the error codes, there are about 6-7 errors getting thrown out, but the most concerning is the fact that the ACC ecu is shown as red (aka not responding).

If you restart the car, it shows as green and you can erase the errors.
I drove for a while with the ACC on and everything was ok.
On my return however, I left the car running in my garage for 2-3 more minutes (so stationary) and I got the same errors all over again.

Anyone had this type of problem before?

stormlv · 05-16-2015, 12:33 PM

Here's a small update...

I left the car in the garage for a bit, then when I got back, I took it for a spin.
Everything seemed to work (tested the ACC).
As soon as I stopped and left the car with then engine running for a few minutes I got the same error back.

This is very very weird.

It looks like the ECU is working correctly, but there's some intermittent connectivity to one of the networks (presumably the Flexray network)

Come to think of it, I got the same error ("Front-end collision warning failure") some time ago (two times actually).
It was in the winter and just thought that the sensors had been covered by snow...

E90Fleet · 05-16-2015, 12:45 PM

Maybe a bad or loose connector somewhere ?

stormlv · 05-16-2015, 12:53 PM

Quote:

Originally Posted by E90Fleet

Maybe a bad or loose connector somewhere ?

Certainly seems like it :|
Problem is I have no idea where to start looking...

E90Fleet · 05-16-2015, 02:15 PM

Id start at the ACC sensor itself, since its the most likely place water could gt into a connector

stormlv · 05-16-2015, 06:12 PM

Quote:

Originally Posted by E90Fleet

Id start at the ACC sensor itself, since its the most likely place water could gt into a connector

I don't think it's the ACC sensor...
The ECU itself stops replying altogether.
ISTA and E-SYS both give errors when trying to access it (once ACC gives a first error).
Odd thing is if you turn the car off for a bit, everything just works again.

Oh well, I'm going to the dealer on Monday

stormlv · 05-17-2015, 04:17 PM

So, as I said, I'm going to go to the dealer.
I coded a few features on my car ("MPerformance" in the kombi, ASS default to last position, etc).
Should I remove the coding before going there?
Also, should I mention that I hooked my car up to Rheingold and saw the errors?

05-16-2015, 10:30 AM	#1
stormlv Human 932 Rep 1,200 Posts Drives: Yes Join Date: Nov 2013 Location: Geneva iTrader: (1)	Weird ACC errors I started getting some weird errors from the ACC. In the dash I get the "Front Collision Warning is inactive" (or something of the sort). If I use ISTA and check the error codes, there are about 6-7 errors getting thrown out, but the most concerning is the fact that the ACC ecu is shown as red (aka not responding). If you restart the car, it shows as green and you can erase the errors. I drove for a while with the ACC on and everything was ok. On my return however, I left the car running in my garage for 2-3 more minutes (so stationary) and I got the same errors all over again. Anyone had this type of problem before? __________________ 2023 BMW M4 CP xDr \| 510HP / 650Nm \| Isle of Man Green \| Photo album Sold 2018 BMW M4 DCT / ZCP\| 450HP / 550Nm \| Sakhir Orange \| Photo album \| Tribute Sold 2014 BMW 435xd \| 360HP / 710Nm \| Estoril Blue \| Photo album 2010 BMW Z4 sDrive35i DKG \| 306 HP / 400Nm \| Space Gray \| Photo album
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05-16-2015, 12:33 PM	#2
stormlv Human 932 Rep 1,200 Posts Drives: Yes Join Date: Nov 2013 Location: Geneva iTrader: (1)	Here's a small update... I left the car in the garage for a bit, then when I got back, I took it for a spin. Everything seemed to work (tested the ACC). As soon as I stopped and left the car with then engine running for a few minutes I got the same error back. This is very very weird. It looks like the ECU is working correctly, but there's some intermittent connectivity to one of the networks (presumably the Flexray network) Come to think of it, I got the same error ("Front-end collision warning failure") some time ago (two times actually). It was in the winter and just thought that the sensors had been covered by snow... __________________ 2023 BMW M4 CP xDr \| 510HP / 650Nm \| Isle of Man Green \| Photo album Sold 2018 BMW M4 DCT / ZCP\| 450HP / 550Nm \| Sakhir Orange \| Photo album \| Tribute Sold 2014 BMW 435xd \| 360HP / 710Nm \| Estoril Blue \| Photo album 2010 BMW Z4 sDrive35i DKG \| 306 HP / 400Nm \| Space Gray \| Photo album
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05-16-2015, 12:45 PM	#3
E90Fleet Lieutenant General 1312 Rep 10,185 Posts Drives: BMW Join Date: Apr 2005 Location: South Africa iTrader: (0)	Maybe a bad or loose connector somewhere ? __________________ BMW if you are reading, I need a job, Please.
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05-16-2015, 02:15 PM	#5
E90Fleet Lieutenant General 1312 Rep 10,185 Posts Drives: BMW Join Date: Apr 2005 Location: South Africa iTrader: (0)	Id start at the ACC sensor itself, since its the most likely place water could gt into a connector __________________ BMW if you are reading, I need a job, Please.
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05-17-2015, 04:17 PM	#7
stormlv Human 932 Rep 1,200 Posts Drives: Yes Join Date: Nov 2013 Location: Geneva iTrader: (1)	So, as I said, I'm going to go to the dealer. I coded a few features on my car ("MPerformance" in the kombi, ASS default to last position, etc). Should I remove the coding before going there? Also, should I mention that I hooked my car up to Rheingold and saw the errors? __________________ 2023 BMW M4 CP xDr \| 510HP / 650Nm \| Isle of Man Green \| Photo album Sold 2018 BMW M4 DCT / ZCP\| 450HP / 550Nm \| Sakhir Orange \| Photo album \| Tribute Sold 2014 BMW 435xd \| 360HP / 710Nm \| Estoril Blue \| Photo album 2010 BMW Z4 sDrive35i DKG \| 306 HP / 400Nm \| Space Gray \| Photo album
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