Battery in my key fob on the way out?

[Jack Ratt]

We had a ride out today over Dartmoor and stopped for a cream tea in Widecombe on the moor. I locked the car with my key fob and set the alarm.

When we returned to the car I pressed the green button on the fob, the cars indicators flashed as normal but the central locking didn't activate. I opened the car with the key and central locking operated correctly. When I started the car the indicators flashed for about 30 seconds and then stopped, then started flashing again for another 30 seconds. This happened 3 or 4 times, then they stopped flashing.

I stopped for fuel and the same thing happened again on start up. The car drove great all day with no problems what so ever but I was half expecting the alarm to go off and may be even immobilize the car.

Anyway drove home with no problems. I got home and locked the car with the fob and then tried to open it again with the fob but it wouldn't operate.

I'm hoping it's just the battery in the key fob, but I'm going away for work in the morning until Friday so don't have any time to investigate till then.

I've got a spare fob so I'll try it and see if it works with that one. I'll see if my new Foxwell scanner can come up with something.

Has anyone had this experience?

 

[colb]

Maytbe not the key battery, my central locking started playing up, didn't always respond to pressing buttons on the fob and didn't get flashes of the indicators when locking. Went straight to the boot loom between lid and body and stripped the outer covering to reveal chaffed wires, none broken just outer plastic on individual wires starting to chaff to reveal bare copper. Wrapped each wire with tape to insulate and central locking was restored to normal. Get the indicators to flash when locking 100% now, not sure but don't think they were flashing for some time but didn't explore the cause before discovering the chaffed wires.

 

[mrscalex]

Don’t think it’s your battery. Agree more likely boot loom.

The battery plays no part other than to open the locks and turn the alarm off. It has nothing to do with starting the car.

 

[Jack Ratt]

I did the boot loom repair a while ago now but I'll check it's still good

 

[mrscalex]

You may get a generic and frankly cryptic error from the ZKE.

It uses German abbreviations to describe the zone on the car. I made these initial notes a while back but never got deeper into it.

HK = HeckKlappe = trunk lid
FT - ? = driver door
BT - ? = passenger door

 

[mrscalex]

I wonder if the alarm is not de-activating, maybe it's disconnected not uncommon) so you can't hear it and the flashing lights are the only indication.

The alarm and the immobiliser are not actually linked as such. So the car is in theory possible to drive with the alarm still activated.

The only way to arm and disarm the alarm is with the remote. Turning the key in the lock operates the central locking but specifically does not operate the alarm.

But I still don't think it's the fob battery as you said it was locking the car okay. But well worth observing the behaviour of a 2nd key. I guess in theory the PCB could be knackered or the rubberoid button is bust and is switching things on but not off. But still sounds more like a loom problem.

 

[Jack Ratt]

My alarm does activate as I've set it off numerous times. The loom was in my mind but as I'd done a repair already I thought may be it was something else causing the problem. I suppose one of the unrepaired wires could be the cause. I'll have a look at the weekend. Thanks again Rob

 

[the Nefyn cat]

HK = HeckKlappe = trunk lid
FT - ? = driver door
BT - ? = passenger door

Been a while since I lived out there, but I'd guess
FT=fahrer tur/drivers door
BT=beifahrer tur/passenger door.

And bear in mind these were designed to be left-hand drive, whether they swapped things around for RHD I just don't know.

 

[mrscalex]

And bear in mind these were designed to be left-hand drive, whether they swapped things around for RHD I just don't know.

Interesting point.

 

[DrWong]

The only way to arm and disarm the alarm is with the remote. Turning the key in the lock operates the central locking but specifically does not operate the alarm

I believe inserting and turning the key in the ignition barrel will dis-arm the alarm if it's been activated, i.e. is sounding. The only way to then re-arm the alarm is with the remote, although the car will be drivable.

At least that was my experience when my alarm went a bit squiffy last year. Instantly resolved when I repaired le loom of doom.

 

[mrscalex]

I believe inserting and turning the key in the ignition barrel will dis-arm the alarm if it's been activated, i.e. is sounding. The only way to then re-arm the alarm is with the remote, although the car will be drivable.

At least that was my experience when my alarm went a bit squiffy last year. Instantly resolved when I repaired le loom of doom.

Yes that sounds right. I just meant turning the key in the external locks does not activate/deactivate the alarm.

From memory when I studied up on the EWS (immobilser) the action of turning the key in the ignition also deactivates the dead-locking. Which you'd also expect. Interesting thoughts on dead-locking here btw:

http://visads.com/bmw.html

 

[DrWong]

Yes that sounds right. I just meant turning the key in the external locks does not activate/deactivate the alarm.

From memory when I studied up on the EWS (immobilser) the action of turning the key in the ignition also deactivates the dead-locking. Which you'd also expect. Interesting thoughts on dead-locking here btw:

http://visads.com/bmw.html

Ah yes, on re-reading you were actually referring to locks and not the ignition barrel

Interesting read at that link. I'm pretty sure I've previously locked myself in the car using the fob and managed to get out by pulling the door handle twice. Or am I missing the point here??

 

[mrscalex]

Ah yes, on re-reading you were actually referring to locks and not the ignition barrel

Interesting read at that link. I'm pretty sure I've previously locked myself in the car using the fob and managed to get out by pulling the door handle twice. Or am I missing the point here??

I don't know if it's implemented on all cars, all BMWs or even all Z3s. And I can't pretend I've ever tested it out before across cars.

But for sure I've had a Z3 with this issue. A little different as the driver door was open and I was in the car and couldn't open the passenger door. This was down to a loom issue (it was the 2.2 project we replaced the whole loom on) but same end result. Couldn't open the passenger door - so wouldn't have been able to in an emergency. In the end I took the footwell trim off, located the relevant pins on the door loom and hot wired them to trigger the actuator.

The Z3 has a crash detection system that does various things, blow the battery connector to stop the main systems (eg fuel pump), put the hazards on and maybe it would release the dead-locking too.

 

[Jack Ratt]

Checked my boot loom repair and all is well. I put my Foxwell scanner on it and did the auto scan and it threw up 2 faults, Engine DME, DMS digital motor electronics, and ZKE Central body.

I open the fault status report and it said "Fuse central locking" Fuse interior light and Central locking, rear lid, open circuit.

Checked the fuses and fuse number 45, 25amp was blown. There are 3 separate fuses for the central locking and the other two were good. The interior light is working so must be an old stored code and the same with the boot lid as my boot loom repair is still good.

Fitted new 25amp fuse for the central locking and all is well again.

This is the 2nd time I've used my scanner and have to say I'm very happy with how easy it is to use.

 

[mrscalex]

Good news on the locks.

I would probably look into the DME error. What was it?