Restraint system fault, abs fault, control systems fault, no speedo, wipers on constanly

[dimitripavlovits]

Hello all,

Apologies, I've seen similar posts here a few times, but none of them has had the answer or I've tried it and it's not sadly fixed my issue.

A few days ago while driving I had multiple warning lights coming on, a car drove but there was the following issue:

- Restraint system failure
- Control systems failure
- Steering assistance failure
- Parking brake fault
- Wipers are constantly on with no way to turn them off
- No speedo
- None of the steering wheel buttons worked
- Power steering gone
- Roof not operational (excessive angle message)

What have I tried?

- Battery replacement, coded, left the car to rest overnight. - This fixed the issue for few hours and then it was back.
- Checked all fuses
- Checked positive and negative cables at the engine bay
- Checked all the cables under the seats
- Removed the battery and put positive/negative clamps together to reset electronics (saw this as a suggestion on one of the posts)

Few things to note:

I drove the car till the battery was full (took 1h from 73% to 99%), next day battery was at 93% - feels like excessive drainage?
The issue goes away if the car sits for a few hours, but comes back after few minutes of running.
While driving sometimes the issue "lessens" and wipers work normally and some fault codes disappear (speedo still does not work)

The Car: BMW E89 Z4 Sdrive 3.0i, 46k miles, recent service ( month ago).

I've attached codereads.

 

[Sun108]

my vehicle is doing exactly the same thing, does anyone have a solution to the problem.

 

[AnubisZed]

my vehicle is doing exactly the same thing, does anyone have a solution to the problem.

I'd say a CanBus error. A failure within the CanBus will affect so many systems as they are all connected. Has any work been done recently, to anything?

 

[Sun108]

Hello
The car had an oil change a year ag. Nothing else. Unfortunately I have not driven the car much. I am embarrassed to say that I have just over 7000 miles since I purchased it in 2014. Now that I want to drive her I think she is punishing me for neglecting her.

I thought of checking what I could before going to a garage. Everything looks spotless except for some rust underneath the car. I teplaced the oil, all the filters and even the spark plugs. I replaced the battery as it was 5 years old. Replaced the wiper relay, cleaned the fuse box with air and W40 contact spray. Checked all tyres.

When I start her up she sounds great. I ran a full diagnostic and the error codes come up. When I checked on the code finder the answers are not specific - it generally points to a voltage/electrical issue.

Help, I even asked the universe to talk to me. I know that the mechanics are also going to confused. When I called a roadside mechanic he said that he had never hear or see a vehicle do this.

Any suggestion within my capabilities will be helpful. I thank you

 

[AnubisZed]

Could still be (IMHO it is) a CanBus issue. Possibly a broken or chewed wire/s shorting out causing the issues, the problem, as almost all systems use the CanBus, is finding it.

 

[Sun108]

Thank you - I will take further look. Someone did asks me if we had rats as they could have chewed some wires. The faulty is intermittent. Last week we went out.All the war lights came on. We drove over 100 miles. Stopped had lunch and drive back and the car was fine. No warning lights. The follodaybwhen I went to start her all the warning lights came on again.

I thought that I’d I threatened to abandon or divorce her she will correct he ways . She is stubborn - I will give it another try today.

I thank you for your input it is gives me the motivation to continue to fix the fault

 

[Sun108]

Hello

I can finally report that the issue has been sorted out. All the crazy faults were due to the ABS unit. I had an auto electrician runa a thorough diagnostic and within minutes diagnosed it to be the ABS unit. I sent it in for reairs and apparenty the fault was in the electronics. It was suspected that there was probably an current surge. I did wonder why the battery supplier gave me a full refund on my battery after just under five years.

I would also recommend that when you change the car battery that you register it correctly. We discovered that the garage that fitted the new battery did not register it completely. These cars are so full of electronics and current variations. We should stop calling them motor vehicles.

I hope this helps for anyone who has a similar issue. I suggest consulting a qualified auto electrician (the good one sare a rare find). BMW and even the independent workshops were quoting in the thousands.

Good luck and safe driving

 

[B21]

Hello

I can finally report that the issue has been sorted out. All the crazy faults were due to the ABS unit. I had an auto electrician runa a thorough diagnostic and within minutes diagnosed it to be the ABS unit. I sent it in for reairs and apparenty the fault was in the electronics. It was suspected that there was probably an current surge. I did wonder why the battery supplier gave me a full refund on my battery after just under five years.

I would also recommend that when you change the car battery that you register it correctly. We discovered that the garage that fitted the new battery did not register it completely. These cars are so full of electronics and current variations. We should stop calling them motor vehicles.

I hope this helps for anyone who has a similar issue. I suggest consulting a qualified auto electrician (the good one sare a rare find). BMW and even the independent workshops were quoting in the thousands.

Good luck and safe driving

It’s a common failure mode..there’s an example on YouTube of someone who replicates that just by pulling one of the abs fuses..

Glad it’s sorted and you reported the fix..