Electrical drain - Fuse 31

[d2d101]

Hi,

I have an electrical drain of around 350 milliamps on a 2000 2.8 z3 and it comes from fuse 31 which has a lot of systems on it. The car has no electrical issues or faults apart from draining the battery. A quick google and there are a few queries on fuse 31 but no one says what fixed it.
Fuse 31 contains:
Anti-theft System
Clock
Electronic Immobiliser
Instrument Cluster
Onboard Computer

I have removed the passenger side glove box and disconnected the modules there. Disconnected the clock, instrument panel, and any plugs under the driver's side. Fixed the loom of doom in the boot.

Does anyone know where the chime module is (I believe it makes the noise when you leave the key in the ignition once switched off)?
Is the Toens (Thermal oil level sensor) control module bolted onto the sump with the switch or is that just the thermal oil switch on its own?

The last step is the onboard computer? Before I take that step has anyone on the forum experienced the same issue and knows what caused it?

Thanks

 

[Rod and Kate]

Hi,

I have an electrical drain of around 350 milliamps on a 2000 2.8 z3 and it comes from fuse 31 which has a lot of systems on it. The car has no electrical issues or faults apart from draining the battery. A quick google and there are a few queries on fuse 31 but no one says what fixed it.
Fuse 31 contains:
Anti-theft System
Clock
Electronic Immobiliser
Instrument Cluster
Onboard Computer

I have removed the passenger side glove box and disconnected the modules there. Disconnected the clock, instrument panel, and any plugs under the driver's side. Fixed the loom of doom in the boot.

Does anyone know where the chime module is (I believe it makes the noise when you leave the key in the ignition once switched off)?
Is the Toens (Thermal oil level sensor) control module bolted onto the sump with the switch or is that just the thermal oil switch on its own?

The last step is the onboard computer? Before I take that step has anyone on the forum experienced the same issue and knows what caused it?

Thanks

Hi, we have a 2.8, 98 Z3 with same problem. Many avenues and pounds spent to no avail. End result and cheaper. Quick release battery connector's and disconnect if stood for more than a few days. Problem solved. Sort of.

 

[d2d101]

Thanks for the information. It seems to be very hard to track down. I have checked all the systems on Fuse 31 except for Exhaust Gas Diagnosis. I can't find a wiring diagram for this. Does anyone have a wiring diagram for this system as I can't see it mentioned in the electrical wiring diagrams?
Did you eliminate Exhaust Gas Diagnosis when you were searching?

If If I can't find it then a quick release or running it from a hot fuse may be a solution.

 

[jaguartvr]

Check the small switches on the door catches on the rear of the door aperture.
They get sticky and are part of the anti theft system. On one of my cars, one was sticky and on occasion, it
left the interior light on causing the battery to go flat. The interior light is so dim it is hard to spot that it is on.

 

[bear2020]

I had a drain on my 3.0 and it was from the boot light. I ended up taking the light out and its never done it since. Must have just been staying on when the boot was shut!

 

[d2d101]

Hi
Thanks for the advice. I have traced it to the white x16 plug into the instrument panel. My next step is to trace and eliminate each system on the x16 connector. I think the airbag control unit might be hard to disconnect. Has anyone else had a drain from the white x16 plug that goes into the instrument cluster?

 

[d2d101]

Hi,

As an update I have removed the centre console to get access to the SRS module and unplugged anything connected to the centre console. I have tried a different instrument cluster as well but still haven't traced the source of the electrical drain on the x16 plug into the cluster.
@Rod and Kate If you ever have time and want to investigate further, I would be curious if disconnecting the white plug x16 into the instrument cluster stops the electrical drain.

How To Guide - Instrument cluster removal

Having removed my instrument cluster recently I thought I would post a "How to" for this job. Tool list : 1. T20 1/4" drive socket and ratchet. 2. Small flat bladed screwdriver. 3. A plastic card ( American Express is good because no one accepts over here.lol.) or similar. 4. A pair of long...

www.zroadster.org

Has anyone else had an electrical drain that stops when fuse 31 is removed. Interesting that @RodAndKate have a 2.8 like me.

 

[d2d101]

Further update.
I removed and unplugged both seats and no luck. Fuse 31 is hot all the time and few things are on when the ignition is off (radio, interior and boot lights). Plus no one seems to have an answer for this which makes me wonder why hasn’t someone disconnected the component and found the electrical drain.

The Pacman OBD port in the engine bay needs the ignition on but the interior OBD doesn’t. When I plug in C110+ reader and remove fuse 31 the reader turns off so the interior OBD is on fuse 31. Pin 12 on x16 (white instrument cluster) is to diagnostic connector.
You can’t unplug the wires to the inside OBD port. When I turned on my c110+ reader it pulled 0.1amps, is this the norm for this reader??
I suspect the electrical drain could be from the inside OBD connector but need to investigate further.
The next step is to plug in the reader to the inside OBD connector and remove x16 from the instrument panel. If the reader turns off then it proves it's fed from x16.

 

[d2d101]

I have confirmed that my electrical drain is on pin 12 (TxD Diagnostic data link) of the x16 connector which terminates in d100 the OBD2 pacman connector in the engine bay. I can’t find x183 as it's not in the driver’s door area. Does anyone know where x183 is located in a right-hand drive car?

What is the purpose of the pins in the pac-man connector cap?

Possible causes of a drain on Fuse 31
X183 splice connector
The cap for the OBD Pacman connector

 

[d2d101]

I have tried a new OBD Pacman connector but that didn't fix it. I see that E39 owners have an issue with x183 but it's not in that position for a Z3. Before I take the interior apart. Does anyone have pictures of a Z3 without the carpets or know where exactly the x183 connector is? The diagram shows inside the driver's door but that doesn't seem right. Any help in locating the x183 splice would be appreciated.

View: https://www.youtube.com/watch?v=5SUJQ740fvQ

 

[Rod and Kate]

Cease and desist move away from the vehicle. This has all gone to far.

 

[bertiejaffa]

I have tried a new OBD Pacman connector but that didn't fix it. I see that E39 owners have an issue with x183 but it's not in that position for a Z3. Before I take the interior apart. Does anyone have pictures of a Z3 without the carpets or know where exactly the x183 connector is? The diagram shows inside the driver's door but that doesn't seem right. Any help in locating the x183 splice would be appreciated.

View: https://www.youtube.com/watch?v=5SUJQ740fvQ

Not sure how it will help but this was my Z3M stripped down

 

[d2d101]

Thanks for the photo. This helps, I don't think x183 is were the diagram shows (driver door) so its a matter of carefully looking.

 

[d2d101]

Does anyone know where this part (Silver connector) is as it looks to have purple and white wires at the bottom of it?
It's not located on the gearbox tunnel as shown in the video.

View: https://www.youtube.com/watch?v=Ov-9LoZKr0k