Electrical gremlins

For the M Powered Z3 derivatives

Moderator: Gazza

Post Reply
User avatar
Gazza
Site Admin
Joined: Tue 04 Oct, 2005 21:58
Posts: 9164

  M roadster S54
Location: East London/Essex

Electrical gremlins

Post by Gazza » Wed 20 Jan, 2016 19:16

I've not used the car for a while, battery went flat so that was removed and fully charged.

Today a variety of electrical gremlins were showing up.

First of all, the fuel and temp gauges weren't moving when I started the engine, also the section where the mileage shows was showng EEP_1

I switched off the engine and restarted, all normal, drove off and the speedo was over reading by 20mph then stopped at 80mph along with the rev counter at 3200rpm.

When I came to a stop, the speedo and rev counter returned to normal, drove off again, the rev counter was working normally but the speedo was still over reading between 20-30mph.

Stopped for fuel, drove off and the heated seats were on but the switches weren't illuminated.

Hopefully it's just a bit of damp got into the circuits somehow :? :?
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

S54 M roadster Image Mustang Fastback, BMW Z1, BMW M3 CSL.

ImageImage

User avatar
Brian H
zroadster sponsor
Joined: Tue 16 Dec, 2008 19:55
Posts: 2502

  Z3 roadster 3.0i

Re: Electrical gremlins

Post by Brian H » Wed 20 Jan, 2016 20:33

If it continues It would maybe be worth clearing the codes etc stored in the ECU, I know from experience the various circuits/services do store low voltage errors.

User avatar
Gazza
Site Admin
Joined: Tue 04 Oct, 2005 21:58
Posts: 9164

  M roadster S54
Location: East London/Essex

Re: Electrical gremlins

Post by Gazza » Wed 20 Jan, 2016 20:37

Cheers Brian, I'll give it a go ;)
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

S54 M roadster Image Mustang Fastback, BMW Z1, BMW M3 CSL.

ImageImage

User avatar
pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3337

  M roadster S50

Re: Electrical gremlins

Post by pingu » Thu 21 Jan, 2016 00:30

Almost certainly a battery problem. Brian's solution will probably cure it.

BMWs seem to get all sorts of problems if they are not used - but they can usually be cured by clearing the codes or resetting the ECUs. The only problem with resetting the ECUs is the car may run rough for a while before the ECUs relearn the correct settings for your car.
Pingu

User avatar
Ragtop
Joined: Sun 26 Jul, 2009 21:38
Posts: 790

  Z3 roadster 2.2i
Location: Bexhill on Sea

Re: Electrical gremlins

Post by Ragtop » Thu 21 Jan, 2016 08:17

I had this happen to me last week. Battery completely flat, I charged it up enough for me to start it, but the fuel, temperature and rev counter would not work at all. After being advised to take the earth lead off for a while and then reconnect, they all worked again. As the old Halfords battery had been in there almost 6 years that l know of I replaced it with a Bosch S5.
Image

bertiejaffa
Joined: Fri 26 Jul, 2013 10:28
Posts: 1715

  M roadster S50
Location: Manchester

Re: Electrical gremlins

Post by bertiejaffa » Thu 21 Jan, 2016 09:12

What is the rule of thumb with batteries? My silver zed has never let me down during the 3 years of ownership. However, this year I havent used it for a while and the battery went flat (left on the car). It was charged up a few times so that I could move the car (Maintenance, rotate wheels and clean the drive but never for a run out) and now when I took it for the MOT the battery would not retain enough charge to start the car regardless of the length of run after being jump started or the amount of time I gave it on my standard battery charger. The end result was a new battery.

I have faced the same problem with my motorbike over the past few years, and the //M. So the question is - if you arent going to be using a car for sometime, what should you do with the battery? I know a few people have theirs on a trickle charger - and I am happy to buy one - but with 5 cars and a motorbike I can't afford to buy 5 trickle chargers nor can I realistically have then continuously connected to the vehicles as there is only room in the garage for the motorbike.

(sorry in advance if this has been a slight thread steal)
Here come the girls.....
Image
My //M Refurb
My First Zed Journal

User avatar
pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3337

  M roadster S50

Re: Electrical gremlins

Post by pingu » Thu 21 Jan, 2016 15:29

A top-tip to reset the car is to disconnect the positive wire from the battery, wait for 30 seconds, and earth it. This confirms that the potential difference between the positive and negative poles are reset to zero.

Another is to disconnect the battery and press the hazard warning switch. This is commonly used to reset alarm problems. I have no idea why this should work, but it sometimes does. The hazard switch is part of the alarm circuitry, so it probably only helps to reset the alarm, not anything else.

Re. Best advice for long term storage. I disconnect the battery. I've never had any problems. You just need to make sure that the boot key works :wink: .
Pingu

User avatar
Gazza
Site Admin
Joined: Tue 04 Oct, 2005 21:58
Posts: 9164

  M roadster S54
Location: East London/Essex

Re: Electrical gremlins

Post by Gazza » Thu 21 Jan, 2016 18:05

Ragtop wrote:I had this happen to me last week. Battery completely flat, I charged it up enough for me to start it, but the fuel, temperature and rev counter would not work at all. After being advised to take the earth lead off for a while and then reconnect, they all worked again. As the old Halfords battery had been in there almost 6 years that l know of I replaced it with a Bosch S5.

The battery is quite old, although it had a charge for 48 hours then a 150 mile run the day before the problems, it was cold overnight.
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

S54 M roadster Image Mustang Fastback, BMW Z1, BMW M3 CSL.

ImageImage

User avatar
Ragtop
Joined: Sun 26 Jul, 2009 21:38
Posts: 790

  Z3 roadster 2.2i
Location: Bexhill on Sea

Re: Electrical gremlins

Post by Ragtop » Thu 21 Jan, 2016 18:21

Exactly the same as mine Gary, it wouldn't hold the charge. I couldn't open the car with the remote, I had to use the key. Another strange thing that happened after l got a bit of charge in it, was as l drove and put the lights on the mileage display went out.
Image

User avatar
Gazza
Site Admin
Joined: Tue 04 Oct, 2005 21:58
Posts: 9164

  M roadster S54
Location: East London/Essex

Re: Electrical gremlins

Post by Gazza » Thu 21 Jan, 2016 22:32

pingu wrote:Almost certainly a battery problem. Brian's solution will probably cure it.

BMWs seem to get all sorts of problems if they are not used - but they can usually be cured by clearing the codes or resetting the ECUs. The only problem with resetting the ECUs is the car may run rough for a while before the ECUs relearn the correct settings for your car.

Would resetting the ECU affect the remap that has been done ?
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

S54 M roadster Image Mustang Fastback, BMW Z1, BMW M3 CSL.

ImageImage

siwilson
Joined: Fri 19 Jun, 2009 10:54
Posts: 782

  M roadster S54
Location: Horley

Re: Electrical gremlins

Post by siwilson » Fri 22 Jan, 2016 11:00

Gazza wrote:
pingu wrote:Almost certainly a battery problem. Brian's solution will probably cure it.

BMWs seem to get all sorts of problems if they are not used - but they can usually be cured by clearing the codes or resetting the ECUs. The only problem with resetting the ECUs is the car may run rough for a while before the ECUs relearn the correct settings for your car.

Would resetting the ECU affect the remap that has been done ?
Sounds like a bad battery. When you have issues in the cold its usually because one cell of the battery is duff. This leads to low voltage and that is what upsets the electronics, even if the car will start. You can try to revive it with a good long charge on a decent battery charger like the CTEK, but likely as not the next cold snap it will happen again. IMO a new battery and leave the old one off for a couple of hours before connecting the new one. No need to rest any codes, but not a bad idea to clean things out. It won't affect your remap, only the adaptions will be lost an even then they are quite minor. I reset mine and it ran just fine.
2001 M roadster S54 Laguna Seca Blue

User avatar
pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3337

  M roadster S50

Re: Electrical gremlins

Post by pingu » Fri 22 Jan, 2016 12:08

AFAIK a remap is hard-coded onto the chip, or may even be a new chip.

As siwilson says, the adjustments may be lost for a while (advance/retard, etc.), but they will sort themselves out within a few 10s of miles.
Pingu

User avatar
Gazza
Site Admin
Joined: Tue 04 Oct, 2005 21:58
Posts: 9164

  M roadster S54
Location: East London/Essex

Re: Electrical gremlins

Post by Gazza » Fri 22 Jan, 2016 16:03

Thanks chaps, new battery it is then :wink:
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

S54 M roadster Image Mustang Fastback, BMW Z1, BMW M3 CSL.

ImageImage

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest