EWS
EWS is the immobiliser system fitted to BMW models with M50 and M52 engines from 1994 onwards. Its basic function was to check that the doors were unlocked correctly and that the correctly-coded ignition key is being used. If it fails to detect the right signal, it will disable the ignition circuit, the injectors and the starter motor, which is a right pain if you're trying to do an M50 or M52 engine swap.
Contents
Components
- ECU
- EWS module
- Key
- Ignition Barrel Ring
- Send/Receive module (under the steering column)
- Loom
The ECU, EWSII and key come as a set. If you have the key and EWSII box, they can be reprogrammed to suit a different ECU by someone with the right equipment. So it is best to ensure you get all 3 components from the same car when purchasing, even see if there are spare keys to be had.
Wiring
To this end, here are the pictures to connect up the EWS system:
M50
M52
Disabling
You didn't think it would be that easy to disable the EWS, did you? And that we'd put that info on a public forum? Good.
The good news is that if you really don't want the hassle of the EWS system, it is possible to deactivate it by swapping in a non-EWS ECU. Essentially, this comes down to replacing the 413 silver label ECU (as fitted to the E36) with the purple-label 413 ECU.
There are other websites (and previously this one) which advocated snipping a green or black/purple wire on your engine loom. We really don't recommend this, unless you fancy cutting off power to your car's injectors.
Reference
Learn more about the EWS system
