Bimmer issues

Good evening, and merry Christmas to everyone.

Every two months or so, the 'check control' system on my BMW 316 reports 'phantom' issues, e.g. problems with tyre pressure, ABS, seat belts. Each time, there are no such issues.

This typically happens in bad rainy weather. The next time I drive the car, the errors always 'disappear'.

The dealer has tested it and said they couldn't find anything. I've been there twice with it.

Last night it happened again, with 5 'errors' being indicated on the panel. This time however, the speedometer also didn't work, i.e. the needle stayed at zero whilst I was driving. Again, this morning everything was fine.

I am bringing it to the dealer on Wednesday but would appreciate any advice or insights. Sorry, I'm not a car person so I may be missing something obvious or not explaining it clearly. Thanks

bazz26

The first thing that I would think of when so many electrical systems being affected would be a dodgy battery or alternator. or a frayed wiring loom somewhere given it mainly happens when it rains. However I'm not a mechanic/auto electrician and would have thought/hoped that the dealer would have checked them as part of their trouble shooting.

Maybe bring it to a good auto electrician to troubleshoot further as it does sound electrical.

Jim79

You say you are not a car person; grand. But you can become one and here is a place for you to start.
First you need a good torch. Have a really good luck around the cars wiring you never know what you may spot. I had an electrical problem and found exposed wires in the engine bay.

next you need to get a voltmeter and youtube. together you are going to learn to check your battery and alternator.

Its a process of investigation. Let us know how it goes.

Del2005

stunner dunner wrote: »

Good evening, and merry Christmas to everyone.

Every two months or so, the 'check control' system on my BMW 316 reports 'phantom' issues, e.g. problems with tyre pressure, ABS, seat belts. Each time, there are no such issues.

This typically happens in bad rainy weather. The next time I drive the car, the errors always 'disappear'.

The dealer has tested it and said they couldn't find anything. I've been there twice with it.

Last night it happened again, with 5 'errors' being indicated on the panel. This time however, the speedometer also didn't work, i.e. the needle stayed at zero whilst I was driving. Again, this morning everything was fine.

I am bringing it to the dealer on Wednesday but would appreciate any advice or insights. Sorry, I'm not a car person so I may be missing something obvious or not explaining it clearly. Thanks

It sounds like a wiring issue and with it being intermittent you'll be throwing money at mechanics and they most likely won't be able to sort it. As said you're going to have to check all your electrical connections and cables for shorts or bad contacts, this will be a tedious job that will cost a fortune in a garage so you'll have to do it yourself.

pa990

If it's only happens during or after rain, then it definitely is an electrical issue.

You'll need to find a good Indy sparky.

In the meantime , it might be an option to spray different sections of the car with a hose to recreate the problem.

You might be able to narrow down, where the issue is originating. This will be time consuming, as you will have to do a different section each day

pa990

BTW

welcome to the B.M. trouble U club

rebel.ranter

You don't mention what model 316 it is e36/e46/e90, that would help a bit.

There is certainly a potential for a link between the water ingress and the resultant electrical gremlins.

Lift up your mats in the various footwells to see if the carpet underneath is wet. The electrical control units are located in many locations including under the bonnet, left hand side (passenger) up by the bulkhead, check for water issues there also.

Special Circumstances

rebel.ranter wrote: »

You don't mention what model 316 it is e36/e46/e90, that would help a bit.

There is certainly a potential for a link between the water ingress and the resultant electrical gremlins.

Lift up your mats in the various footwells to see if the carpet underneath is wet. The electrical control units are located in many locations including under the bonnet, left hand side (passenger) up by the bulkhead, check for water issues there also.

Now that you mention it, lad at work at problems due to water filling up the well in the boot that the battery sits in. 06 320d not sure if applicable here.

Del2005

pa990 wrote: »

If it's only happens during or after rain, then it definitely is an electrical issue.

Friend of mine had a car that blew its master fuse nearly every time it rained and they stopped at lights, to such an extent that they carried a good few spares. After a good bit of investigation it turned out that there is a fuse box in the passenger foot well that was getting kicked and blowing the fuse. Car hasn't blown a fuse since. So something that only happens in the rain doesn't necessarily mean that the rain is the cause.

happynetguy

Anyone know a mechanic with experience using the z4? Would be good to hear from you.

Del2005

Del2005 wrote: »

It sounds like a wiring issue and with it being intermittent you'll be throwing money at mechanics and they most likely won't be able to sort it. As said you're going to have to check all your electrical connections and cables for shorts or bad contacts, this will be a tedious job that will cost a fortune in a garage so you'll have to do it yourself.

If it is intermittent are you actually suggesting a visual "check all your electrical connections and cables for shorts or bad contacts", that's more or less impossible unless the chap strips the car.

The only remotely logical thing to do here is find a good auto electrician. The vast majority of mechanics know next to nothing about vehicles electrics and many were lost in FAS at the mention of the subject.

DublinDilbert

I'm guessing this is an e90?

That many faults, I would guess it's the main can bus going down not allowing things to talk. Many of these faults will self clear once the bus starts running again.

It's a few years since I've touched an e90, look at the can connections, the module which acts as the can bridge (can't remember the name of it) and the engine ecu.

On the e90 water can get into the plastic container with the engine ecu, the drain hole in the bottom is often blocked. If she was a non starter with all them faults I would suspect water in the engine ecu.