Multiple failure indicated

[Smartbear]

The battery is the first thing I checked, and it was very healthy and still is. This is exactly what I am experiencing..

https://www.youtube.com/watch?v=k8bJegVxo_c

Hello all, I think I may have narrowed the issue down to the main (black) power relay located on the junction box, apparently it was not seated properly! to check the effects of this I pulled it completely out and the car went into CRAZY mode like before which subsided when I reinstalled it, also the running temperature of this relay is a bit warm to the touch, not sure if this is normal so I bought a new replacement just in case to verify.

Nope! not the relay but still definitely seems to be power related. After I changed the relay, all was well for a while, but weird things would keep happening like, lights refusing to turn off, boot not opening with the remote and the aux. port switching off. Simultaneously during the hiatus period, I purchased and installed a P3 gauge which allows me to see battery voltage (among other things) which read normal at the time around 14.2V with the motor at idle. Recently the symptoms have returned and are occurring with a greater frequency as if it's on a timer, so I decide to purchase a brand-new battery just to eliminate it from the suspect list, but this made no difference! two days ago on my way home from work I decided to observe the battery voltage, what I saw was confusing, alarming but relieving! When on the gas the voltage would be 12.5V-12.7V and when I get on the brake it would jump up to 14.2-14.5! Clearly the alternator/regulator is not functioning correctly, and the battery is running things until its power is depleted after which the craziness starts (at least this is what I hope is happening!). I have since bought a new regulator as the alternator only has 22K km on it, so I doubt is physically bad, after I install, I will post my findings again.

Cheers!

The voltages you’ve measured are normal for an e89, they don’t charge at a uniform rate like the older model due to the ibs - it puts more load on the alternator during braking to lessen the parasitic load when accelerating/cruising.
Rob

 

[flybobbie]

Yet the voltmeter i fitted never shows any voltage change.

 

[Smartbear]

Yet the voltmeter i fitted never shows any voltage change.

Maybe your ibs has gone faulty? The charging rate should definitely vary
Rob

 

[RobbiZ4]

[/quote
Maybe your IBS has gone faulty?

Good idea. I heard about a faulty IBS some days sgo and got it today for further investigations. I don't know what and how to measure, but I will be able to mount the old one into my Z4.

 

[dumaurier7]

[/quote]

The voltages you’ve measured are normal for an e89, they don’t charge at a uniform rate like the older model due to the ibs - it puts more load on the alternator during braking to lessen the parasitic load when accelerating/cruising.
Rob
[/quote]

I think you may be correct! I continued monitoring the voltages displayed and they do cycle between 14.5 and 13.2 fairly constantly which suggests that the charging rate is constantly being adjusted. I have now exhausted all the options I could think of so I have now enlisted the support of a local BMW specialist, will report back with findings.

 

[dumaurier7]

[/quote]

I think you may be correct! I continued monitoring the voltages displayed and they do cycle between 14.5 and 13.2 fairly constantly which suggests that the charging rate is constantly being adjusted. I have now exhausted all the options I could think of so I have now enlisted the support of a local BMW specialist, will report back with findings.
[/quote]

I have not had the issue since recently swapped out the battery for the brand new one (shown below), however, I three issues still persist.
1. My A/C is nonfunctional, everything is throwing a fault in the system!
2. The exterior lights (head, park and third) occasionally remain on.
3. The trunk does not unlock with the key fob anymore.

 

[matsmith749]

OK - so it was the battery after all that?

Remember months ago, when i told you so.

 

[dumaurier7]

OK - so it was the battery after all that?

Remember months ago, when i told you so.

 

[dumaurier7]

So it started again! Don’t think it’s the battery anymore!

 

[B21]

Was the new battery registered ?

 

[dumaurier7]

Yes it was.

 

[B21]

Yes it was.

So what codes are you getting? What code reader are you using?

 

[dumaurier7]

I am using Bimmer Greks on my tablet, before the event starts there are no codes then BOOM! It goes into CRAZY mode the wipers turn on and everything starts throwing codes and turning on the all the warning lights .

 

[B21]

Seems like a can bus related event…

https://www.youtube.com/watch?v=E5lsGcQxebs

 

[dumaurier7]

Yep! I’m thinking the same, will be taking it to a BMW specialist to get this sorted once and for all.

 

[dumaurier7]

I have not had the issue since recently swapped out the battery for the brand new one (shown below), however, I three issues still persist.
1. My A/C is nonfunctional, everything is throwing a fault in the system!

AC module was defective! same replaced now all is good.

2. The exterior lights (head, park and third) occasionally remain on.
3. The trunk does not unlock with the key fob anymore.

CAS module was defective had a replacement coded and installed now all is good again.


Seems like the initial battery failure did cause a lot of electrical damage.

 

[dumaurier7]

The wipers staying on is a good indicator here.

Abs modules fail, causing garbage signals to be poured into the canbus, hence modules cannot talk to each other. PT-can is not affected, hence no limp mode.

Mike

Hi all! Seems like this diagnosis is correct! The indept scan shows that during the event the ABS module is not communicating at all, and according to the Technician, the reason for the intermittent behavior could be heat related. For now, I will try sticking some heat insulation on the cover of the module while I wait on a replacement.

 

[dumaurier7]

Update time! whilst waiting for a replacement I pulled the module (which is in like new condition!) off, gave the board and connector a good spray with CRC contact cleaner and I stuck some nice'n heavy heat insulation to the black cover before putting it all back together, it's been two days now with no unwanted driving experiences!

 

[dumaurier7]

Finally was able to swap out this module, I now have no warning lights and the car behaves normally now! I think (HOPE and PRAY! ) that this is the final solution!

 

[B21]

Finally was able to swap out this module, I now have no warning lights and the car behaves normally now! I think (HOPE and PRAY! ) that this is the final solution!

Good to have the update