Electrical experts --> I need your help (central locking)

[beinet1]

Hi all,

I have had a central locking issue since I bougth my car for nearly 2 years ago. I have tried several times to find a cure for it without any success.

Symptoms are as follows:
- Car wont lock using the remote key fobs, but unlocks fine.
- The car locks fine using the center console button.
- If I disconnect the battery for a few seconds and reconnect (or pull the BCU fuse), the car locks and unlocks fine with the remote until I turn the key in the ignition for the first time. The symptoms are then back and remote locking wont work.

So far I have tried the following things:
- Replaced key fob batteries
- Did a battery reset
- Replaced the BCU as reccomended by my local ex-rover garage --> http://forums.mg-rover.org/showthread.php?t=405371
- Looked for damaged wiring in the front doors.

I still have no clue.
After reading several forum threads, it seems to me that the problem migth be related to the K-bus system as I have read about similar issues on this forum. I do not have any FBH or sat nav in my car.
I have read somwhere that there is K-bus connectors located below the carpet in the footwells that my corrode due to water ingress. I have removed the covers in the footwells and lifted the carpet at the sill side. I can`t find any connectors here. Do I have to completely remove the carpet to find any "secret" connectors??
I have also checked the blue, red and greyt connectors tucked up in tape located right behind the ligth switch and beside the fuse box. No corrosion here.
I have to mention that the foam under the carpet is damp. I think this is "left overs" as the car had a serious boot leak when I got it.

Any advice would be greatly appreciated.

[marinabrian]

Check very carefully the wiring to the EWS immobiliser
Brian

[Lovel]

Originally Posted by marinabrian

Check very carefully the wiring to the EWS immobiliser
Brian

Also inspect inside EWS. A previous case like this turned out to have corrosion inside it.

[beinet1]

Hi,

Thank you for the tip. I have checked the EWS connector and inside the EWS module. It looks like new. No corrosion or traces after water. Still no joy

[ianfletcher]

I had this problem when i bought my car and all the symptoms were the same as yours.

Your fuse for the alarm sounder has blown.

It's fuse 36 and It's a 5 amp.

[beinet1]

Hi all,

I take my hat off and eat it......

After nearly two years of ownership with this car and doing several attempts to cure this problem which has involved a lot of thinking, fault finding and even a new BCU and programming of this, the problem is finally solved!!
I pulled fuse #36 and found this:


Replaced it and everything is fine!!!
I am both happy and gutted on the same time... Feeling pretty dumb for not checking a basic thing like this first...

I have to partially put the blame on the previous owner which had carried out a fault finding process at an ex-rover garage which concluded with a broken BCU. I just continued on this and expected that they had carried out the basic checks...

Anyway, Thank you very much for the advice

Lesson learned will be: do your "homework" and do the simple checks first

[ianfletcher]

Just make sure your alarm sounder or bbus is working as my bbus isn't working and I think this is what caused the fuse to blow

[james duffy]

I have same problem i just pulled out all 5 amp fuses none were blown but when i was finished the the locking worked then i started car then once i stopped the engine it all went pear shaped again does any one have a diagram of fuse box for an mg zt 190 2003 model i dont have a manual thanx

[chris75]

Originally Posted by ianfletcher

Your fuse for the alarm sounder has blown.

It's fuse 36 and It's a 5 amp.

That was very impressive
Do you know this weeks lottery numbers ?

[james duffy]

Yes it was for 5 mins an yeah a do this wks numbers wld you like them after the draw