I own a BMW X5 3.0D sport on a 2004 plate, I came to start it today after I'd driven it to the lake district and it was completely dead on the key, all the lights on the dash came on and everything was working fine but nothing would happen with the engine it wouldn't even turn over, I locked the car again incase it was an alarm issue, I waited for the red light to flash to say the alarn was set and then unlocked the doors and tried to start it again and nothing on the key again. I spoke to my bother in law who told me to disconnect the battery leave it a minute reconnect and try it again. After the 2nd attempt it started, I drove the car home which is about 45 miles. I parked at home and after an hour went out to start the car, and again nothing. All the dash lights come but when you turn the keyto start nothing happens! Any help would be much appreciated. 

Gaz

Try another key if you have one. Mine failed on the chip and the ews unit didn’t recognise the key. 
the remote locking will work as it’s a separate transponder. 
mid you can get a copy of pasoft or another diognosis tool, plug the car in and you can see the car trying to talk to the key. Mine would drop in and out of the comms and fail to start the car. I put the spare key next to the barrel and it read and started all the time. 
I bought a blank key and a programmer, got a local locksmith to cut the key and copied the chip contents onto the new blank. 

No issues since! 

Morning Gareth

A scan would be my place to start, your issue could be a failed relay or starter a blown fuse or failing ignition switch even the gearstick inhibitor switch (try starting in N)

The fact that the battery disconnect seemed to work as it reset all fault codes temporarily. Get someone with BMW1.4.0 or INPA or a BMW capable Fault reader to scan the car and go from there

Good Luck

Dave

On 4/6/2022 at 11:15 PM, X5smw said:

Try another key if you have one. Mine failed on the chip and the ews unit didn’t recognise the key. 
the remote locking will work as it’s a separate transponder. 
mid you can get a copy of pasoft or another diognosis tool, plug the car in and you can see the car trying to talk to the key. Mine would drop in and out of the comms and fail to start the car. I put the spare key next to the barrel and it read and started all the time. 
I bought a blank key and a programmer, got a local locksmith to cut the key and copied the chip contents onto the new blank. 

No issues since! 

Thanks for the advice I'll give it a go, I was wondering if it might be the battery in my key, I've had 5 years and never changed the battery in the fob!! I'll dig out my spare key and give it go! Thanks again mate 👍🏻 

 

1 hour ago, Greydog said:

Morning Gareth

A scan would be my place to start, your issue could be a failed relay or starter a blown fuse or failing ignition switch even the gearstick inhibitor switch (try starting in N)

The fact that the battery disconnect seemed to work as it reset all fault codes temporarily. Get someone with BMW1.4.0 or INPA or a BMW capable Fault reader to scan the car and go from there

Good Luck

Dave

Thanks for the advice matey, I'll try n find some1 with a fault reader and see what's coming up on it! Just keeping fingers crossed it's nothing major!! 

The battery should keep charged as it charges off the ignition barrel.

the battery would not make a difference as the chip for the immobiliser unit is benign. The battery controls the remote central locking. 
I worked out why mine kept failing by using PAsoft. The diagnostics software showed the ews only reading the key chip intermittently. A great price of kit and very cheap. 
good luck and keep us informed