immobiliser problem please help!!!

frankmasterjam

frankmasterjam

Newbie
British Zeds
Joined
May 2, 2025
Points
4
Location
leeds
I’ve recently just bought a z3 1.9 98’ with the m44 engine. got it home and drove it spot on. however the other day i drove it to work and when i finished the car wouldn’t start up, no crank nothing. i rang the aa and they said the starter motor is good but there’s no feed getting to it, he suggested it would be the immobiliser switch but im very confused and don’t know how to fix this issue due to me being new to the car community.
 
When you switch the ignition on are you getting the dash lights lit up?
When you switch ignition on the car reads a code in the key to verify its the correct key this code must match what is held in the cars computer and the EWS module that controls locking and security codes. If the code matches what's held in it, it allows the starter to be released so that when you turn the key to the start position it powers the starter motor. As an added security feature the car gives the transponder in the key what they call a rolling code which must match the next time the key is used. It is not unknown for the synchronization between the key and the EWS /DME car computer to fail which requires it to be resynced. This can be done with BMW software and higher end obd2 scanners to resync the modules.
 
Worth updating your user details to show your location, someone near you may be able to offer some assistance.
 
As these systems get older they will start to cause problems. The easiest and cheapest fix is to send off your ECU and have the EWS system, (immobiliser) disabled.

FYI, if the Immobiliser is not activating you wont hear the fuel pump prime and no 12v supply to the injectors. This will also show as a code in the DME when scanned.
 
Hi. Currently have the same problem here. 1999 2.8. The immobiliser is triggered if you try starting the car with a flat battery. Would be interested in sending the ECU to be modified. Where would I send it.? Alternatively is INPA the current favoured software or is there anything less complicated. Will any of the current sub £500 scanners do the job. Thanks.
 
Lee said:
As these systems get older they will start to cause problems. The easiest and cheapest fix is to send off your ECU and have the EWS system, (immobiliser) disabled.

FYI, if the Immobiliser is not activating you wont hear the fuel pump prime and no 12v supply to the injectors. This will also show as a code in the DME when scanned.
Click to expand...

Does the immobilizer kill the starter motor?
 
hi there, i sent my ecu off to get the Ews code disabled and it’s still got the same problem. it started and i had an hour drive turning it off and on until i arrived back home i turned it off and thought i’d try to turn it back on and it stopped again. any other things i could try?
colb said:
When you switch the ignition on are you getting the dash lights lit up?
When you switch ignition on the car reads a code in the key to verify its the correct key this code must match what is held in the cars computer and the EWS module that controls locking and security codes. If the code matches what's held in it, it allows the starter to be released so that when you turn the key to the start position it powers the starter motor. As an added security feature the car gives the transponder in the key what they call a rolling code which must match the next time the key is used. It is not unknown for the synchronization between the key and the EWS /DME car computer to fail which requires it to be resynced. This can be done with BMW software and higher end obd2 scanners to resync the modules.
Click to expand...
 
Hi lee, i recently sent my ECU off for the EWS disabling and it’s still doing the same thing. i took it out when the ecu arrive for about an hour and when i came back home i turned it off and tried to turn it on again and it just stopped starting again. do you know anything else that could fix it?
Lee said:
As these systems get older they will start to cause problems. The easiest and cheapest fix is to send off your ECU and have the EWS system, (immobiliser) disabled.

FYI, if the Immobiliser is not activating you wont hear the fuel pump prime and no 12v supply to the injectors. This will also show as a code in the DME when scanned.
Click to expand...
 
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