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1995 E36 m3 immobiliser/ews problem

33K views 72 replies 8 participants last post by  19-bad 
#1 · (Edited by Moderator)
hi guys, i have a '95 3.0 m3 with a std bmw alarm(3g) mk1 and ews

over winter the battery died, i dont know how long for as i dont use the car in winter.
when i charged it back up the car had forgotten the alarm remote.
i could lock/unlock the doors with the key but not the alarm remote.
after a bit of meessing about, with the key and buttons, i got the remote working again.
now the alarm works as it should, but i cant get the car to start
it was all working fine when i parked it up.
when i turn the key i get ign lights, but then turn to crank and nothing happens.

i can hear any relays clicking, no starter, cant hear the fuel pump priming but not sure if i should?
theres a permanent live at the starter but no signal when cranking.
does this sound like a ews/immobilser fault?

nothing i do will make the car start.
any ideas on how to get the car going again?
cheers
 
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#32 ·
All doors have to be closed, including the boot and bonnet for the double lock to work !
Are all the sensors on the doors, boot and bonnet working ?

I'm surprised that the gear off your dads car hasn't worked ?

Have you tried pushing this car, putting it in gear, and dropping the clutch ?
It could be a stuck starter motor/solenoid... Or has this been mentioned previously on the thread ?
 
#33 ·
all doors/boot bonnet were closed, i just tried it again just incase.
still nothing. all sensors work cos the lights come on/off windows go up/down when u open/close the doors.
bonnets shut cos the alarm beeps if its not, boots closed cos gthe lights off.

it was no different with the parts from his car fitted,

haven tried pushing the car as its wiring to the starter thats not working not the starter itself.
i know i have a live from the key to the ews but no live from the ews to the starter or the dme.

plus if i pushed it off my drive i couldnt get it back on. lol
 
#34 ·
Can't think why the starter didn't operate with all the parts off the other car.
Did you definately confirm the live at the EWS was the one from the ignition in start position? (there are other lives at the EWS unit). If so, you could short across from that wire to the one that goes to the starter temporarily, then turn the key and see if the starter turns - just to be sure that circuit is ok.

You have checked all fuses - No.31 for EWS and No. 45 or 46 for transmitter.
 
#35 ·
yep checked all fuses, they are all ok and getting a live at the ews from the fuse box and from the key in p3, but no live out from ews wvwn with dads parts on there.

i could bridge the starter but the car still wont run cos the ecu isnt getting a signal from the ews so wont tell the fuel pump/injectors to work.
that will show the starter working but wont answer the problems with the car.
ill do it in the mornin, but i know theres a fault with the ews box cos with a test light plugged in it im not getting anything out.
 
#36 ·
Get a thick wire, connect one end of the wire to the positive post near the brake master cylinder, and stick it on the starter motor.

Get the car started !

Let's see if it's a stuck starter motor or not !

EDIT: You posted while I was reading electrical diagrams. Just get the car started, rule out the starter.

The reason I say this, is because your saying that the DME isn't getting a signal from the EWS... But what you've got to remember, is that this is a 2-way DATA line. The EWS doesn't just output 12v, and the DME see's 12v !

The ISN received from the EWS II module during start-up is compared to the internal
ISN of the DME. The numbers must match before the start operation is allowed to continue.
ISN = Individual Serial Number.

The EWS and DME are trying to exchange numbers to see if they match.
 
#38 ·
i can bypass the ews to see what the starter does, actually ill do it in the break of the bourne ultimatum im watching now lol.

so the wire from the ews-dme, does this request a code from dme then back to ews telling the starter to start, when u turn the key?
 
#41 ·
so the wire from the ews-dme, does this request a code from dme then back to ews telling the starter to start, when u turn the key?
The key is inserted into the barrel and switched on. The transmitter/receiver module sends a 125kHz AM signal to the induction ring. The AM signal induces voltage in the key coil and powers up the transponder.
Powered up, the key transponder sends the key identification code to the transmitter/receiver module via the 125kHz AM signal. The transmitter/receiver module converts the AM signal to a digital signal and sends it to the EWS.

The EWS control module verifies the key identification code and checks to see if the key is enabled.
Upon accepting the key as valid and enabled the EWS sends a digital password to the transmitter/receiver module, which converts the data to an AM signal and sends it to the transponder via the induction ring.

If the transponder accepts the password as correct the transponder releases the changing code to the transmitter/receiver module which converts this AM signal to digital and sends it to the EWS.

If the changing code received by the EWS is correct, and with correct input status the internal starter relay is energized and the starter motor begins to operate. At the same time the EWS module sends the ISN to the DME via the single wire communication link.

If the ISN code stored in the EWS matches that of the DME, the drive away protection is cancelled, the injection and ignition is enabled.

During the process of sending the ISN to the DME, the EWS sends a new changing code to the transponder through the transmitter/receiver and ring antenna.

This all happens within 750ms !
 
#39 ·
Right, i've been out to test my car, as I have 2 keys for it, 1 that IS recognized by the EWS, 1 that ISNT recognized.

Locked, with unrecognized key = No unlock
Double Locked, with unrecognized key = No Unlock
Locked, with recognized key = No unlock
Double locked, with recognized key = Unlock

The car has to be double locked, which means you turn the key once in the locked position (And as long as every door is shut properly) then it should double lock - The double lock is confirmed by the locking of the petrol flap, and the obvious one, unable to open from the inside of the car !
 
#40 ·
right, i just went and bypassed the ews unit on the starter circuit.
i connected a 3mm wire from the key side to the starter side of the ews, the car instantly cranked over on the key as per normal.
BUT wouldnt start.

i dont know if my car is too early to double lock or something but it doesnt do it.

if i turn the key twice in the lock, it locks the doors once, petrol cap doesnt lock(dont think it can, i cant see any locking mechanism for it) and if i open the interior handle the first pull unlocks the car, 2nd pull opens the doors.
 
#42 ·
im confused as to why the car wont run with my dads parts fitted then.
by bridging the cable thats proved all the wiring to the starter works.
so even if the car didnt start with his bits fitted it should have at least cranked over.
why doesnt it try that with his key/ews/dme fitted.
damn thing. all the fuses and relays have been checked and are working.
as many earths as i could find are checked and working.
it sounds like its definately ews/key related to me. somehow lol
 
#43 ·
I'm starting to run out of idea's here mate.......

What cable did you bridge ?

Next thing to try, could be the transmitter/receiver module from your dads car. This is what is used to convert the AM signal, to digital.
If this has malfunctioned, then it'll be unable to convert the signal, which could explain why your gear doesn't work, and then when you try your dads gear, it still doesn't work.
 
#44 ·
i bridged pin 1 and 3 on the ews, they are from the key p3, and out to the starter. that cranked it as normal then when i turned the key, i basically bypassed the starter imobiliser circuit.

ive put the transmitter from his car on, still didnt work. lol
 
#45 ·
Ahhh, I thought you meant you stuck a power feed straight to the starter... Then you mentioned about it proving the wiring, so was a little confused.

So you've tried the transmitter......................................................................... The ONLY thing I can think thats left to try is the interior wiring loom, and engine bay wiring loom, but I suspect your dad wouldn't be too impressed by this :lol

Maybe try talking with 'TheEnd' about an EWS-delete.

But as it's an M3, i'd highly recommend getting another type of immobilizer fitted.

To be honest, I wouldn't be too happy about going down this route.... Maybe an auto-electrictian could trace a wiring fault between the EWS module and the DME ?

Or even BMW. But that'll cost an arm and a leg.
 
#47 ·
ive got a mate whos a mechanic. im gunna ask him to take it to work and look at it afterwork/lunch for a bit.
its not a daily driver so doesnt matter how long it takes.

failing that a specialist (b&w has been recomended by a mate)

thanks for all the help mate.

i do have a clifford alarm i could get fitted but i wanted to fix the fault with the car rather than go around it.

ill let u guys know how i get on anyway.
 
#49 ·
These things are like crosswords. After a while you just have to take a step back and look afresh.

Have you tried unplugging the 3G alarm module? Just because its responding doesn't mean it isn't hanging the system somehow. Unplug it, lock the car, unlock and try again.

Does your car have the full 18 button OBC? A feed from the code function locks the immobiliser out. You could try unplugging that too.
 
#50 ·
Just been for a shower, and had a think about it (this is how dedicated to BFUK I am :rofl).

Is your central locking working (Apart from the double lock) ?
Can you do a continuity test for the earth wire for the EWS module ?
It's possible that this double lock and EWS are maybe linked with a common ground, and it's failed ?
Also check for power at the EWS module.

Second thing I was thinking about, and I really don't mean to insult your intelligence mate, but when you say your swapping the EWS module around, where's this module located your swapping ?
From what you said so far, I think you've got the correct module, but I just want to make sure.
 
#51 ·
lol it looks like this is confusing u 2 as much as it is me. lol

billy, yep unplugged the alarm a few times, but havent tried locking/unlocking the car manually with the alarm unplugged. i will try that tomorrow morning.

18 button obc, yes, ive never pressed the code button before, but i will try unplugging it.

ferret,
yes, alarm is working as normal, so is the central locking. all normal.

tested earth at the ews, yep, its working. so is the power from fuse 31.

not insulted.
the ews is a small black box behind the glovebox with a large yellow plug.
 
#55 ·
Clutch Hall sensor was fitted from Jan 1997 onwards.

In theory, having swapped all your Dads bits over the car should start, but it doesn't. This suggests either something in the cars wiring is still telling EWS to immobilise or its nothing to do with the immobiliser.

Leaving option B aside for the moment I wonder if the CL system is only sending a single unlock signal instead of the double. When you unlock the doors either with the remote or with the key do the door pins jump up freely or are they sluggish / stiff?

You've tried locking & unlocking on the passenger side?
 
#57 ·
The first signal is from the door solenoid, the second signal is from the lock itself, hence "double lock". The 3G system activates the CL (1st signal from the solenoid) then adds the second signal itself via the loom. To be unset EWS must also have both of these signals, either from the lock itself or via the 3G alarm, otherwise you could just screwdriver the lock and EWS would unset.
 
#59 ·
I LOVE YOU GUYS! :d

now im not sure entirely what i did anymore, but it runs.

i unplugged the obc, disconected the alarm, locked/unlocked the car, rechecked the fuses, disconected the battery over night, refitted all my original ews related parts, and hey presto it works.

ive gotta put everything back together yet but im already late for work so that can be tonights job. lol

thanks a lot for the help fellas.
if it stops working for any reason when i put it back together ill let you know but for now all is good.

:applause:applause:applause

gotta rebuild my dads car now to. lol
he doesnt know i stole anything yet. lol
 
#60 ·
I LOVE YOU GUYS! :d
I'm feeling the love :rofl

gotta rebuild my dads car now to. lol
he doesnt know i stole anything yet. lol
It's not technically stealing, as you'll be replacing the bits :hihi

Glad it's sorted. Add the alarm first, then test the car, then add the OBC and test the car.

Hopefully that way, you'll be able to pin point what is causing the issue.

I suspect it might be the OBC, as IIRC, you've already had the alarm disconnected.
 
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