1.9 M44 EWS 3D Issues

Matt Barnes

Matt Barnes

Zorg Guru (III)
Supporter
British Zeds
Joined
Jul 18, 2020
Points
134
Location
Portchester, Fareham
Model of Z
1998 BMW Z3 Individual 1.9 M44 B19
Morning!..I have the classic Crank No Start issues after restoring my 1.9 (off the road for 3 years). Car runs fine for 3 seconds in limp mode (ICV and TPS unplugged). My routing around is pointing to the EWS 3D Immobiliser. Mine has the thick Green/Black on Pin 1 and thick Yellow/Black on Pin2. My Green Pin10 sits at 13v output with the key in and drops to around 7v at Position 1. Ties in with my scanner reporting Terminal 30 Ok at key in and Terminal 30 Not Ok at Positions 1 and 2. If I pull Fuse 45 I get Terminal 30 Ok in all positions but obviously now the Immobiliser is in the Disabled state. I get Released status when plugged in, so EWS is reading the key ok. I have pulled the Instrument cluster to rule that out and at rest with the key out, I get only 20mA draw from the battery. Would anyone have a circuit diagram for this model of EWS 3D?... many thanks!
 
My pin 10 does that too. Although mine is 11-and-a-bit-v. Not 13v

20260810_102813.webp


Going down to 7-and-a-bit
20260810_102833.webp


Assuming of course that I'm measuring the same pin as you are. SHow me which pin you're measuring - if it's not the same one as me.

BTW. I changed my fuel filter yesterday and the car ran for 3 seconds and then died. Multiple times. It took time to fill up the filter and pressurise the fuel rail. When it happened i immediately thought of you with your 3 second running.
 

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Last edited:
thank you @Duncodin for all this.... most of the detail is on my restoration thread, but in essence this is what I get ..

1786356471439.webp


noting that I replaced the battery with a fully charged one and pins, 7, 10 and 15 went to 13v with just the key in

1786356566947.webp


so my Pin 10 is second one in on the top row in this picture

my issue is, when I turn the key to Position 1, Pin 10 drops to about 6v. At the same time my Scanner goes from Terminal 30 Ok, to Terminal 30 Not Ok.

My Key/EWS/DME connection is fine as DME Status is "Released" and Terminal 30 ok with the Key in. Then get "Terminal 30 Not Ok" for key position 1 & 2. The car cranks due to the Released State but the DME won't let the injectors fire.

Funnily enough, If I pull Fuse 45, Terminal 30 stays OK for all key positions, but obviously now the EWS status is "Disabled".

So something somewhere is pulling that 12v down.... Google suggests it's a relay inside the EWS, but other sites suggests Pin 10 is a 12v input
 
That's the green one I'm testing. As you can see on the multimeter in my picture the v drops to 7.7 as soon as I turn the key.
 
Duncodin said:
That's the green one I'm testing. As you can see on the multimeter in my picture the v drops to 7.7 as soon as I turn the key.
Click to expand...
yep the Green Pin 10.... looks like we have exactly the same thing ! ....... I cannot find a diagram with the 3D pin layout I have. Apparently the 3D is more like the EWS 2 than the EWS 3 or 3.3. I removed my instrument cluster and disconnected it and Pin 10 at rest went to 12v from about 7.

I thought I'd cracked it... then on turning to position 1 it dropped to 6v... something in that Fuse 45 line is bringing it down, as with Fuse 45 out I get "Terminal 30 Ok" on all key positions.... so weird !
 
Yeah - there's a lot of different wiring diagrams and google/ai is no use whatsoever mixing up the different EWS pins from many different bmw chat forums which is where it gets its info. ai is only useful if you give it proper instructions and parameters. Trusting it explicitly is the road to destruction.

Anyway. Let's look at this slowly.

Seen from the connector side:-
Screenshot 2026-08-10 at 12.06.00.webp

Flip that up to the wire side pin #1 is now top left - thin white one if I'm not mistaken. The fat green/black one on the top right is pin 8

20260810_115849.webp


Bottom row, second from the left, the blue one, is pin 10. This goes to the sensor ring around the key barrel. It's not permanent live.

So where is permanent live.

Look at the diagram. Pin 2 is live from the fusebox.
Screenshot 2026-08-10 at 12.25.06.webp

So pin 2 is where you should measure your permanent 12v

Of course, I could be wrong here. But when I've finshed my coffee I'll go out and measure my pin 2 to see if it is permanent live.
 
Duncodin said:
Yeah - there's a lot of different wiring diagrams and google/ai is no use whatsoever mixing up the different EWS pins from many different bmw chat forums which is where it gets its info. ai is only useful if you give it proper instructions and parameters. Trusting it explicitly is the road to destruction.

Anyway. Let's look at this slowly.

Seen from the connector side:-
View attachment 368441
Flip that up to the wire side pin #1 is now top left - thin white one if I'm not mistaken. The fat green/black one on the top right is pin 8

View attachment 368440

Bottom row, second from the left, the blue one, is pin 10. This goes to the sensor ring around the key barrel. It's not permanent live.

So where is permanent live.

Look at the diagram. Pin 2 is live from the fusebox.
View attachment 368443
So pin 2 is where you should measure your permanent 12v

Of course, I could be wrong here. But when I've finshed my coffee I'll go out and measure my pin 2 to see if it is permanent live.
Click to expand...
I think if you flip the drawn connector up the other way... Pin 1 is Top right... so the thick Green/Black is Pin 1. Pin 1 - Pin 8 is the wider row on the connector. So Pin 1 in your photo is top right and Pin 8 is Top left. Pin 15 is the Violet/White one bottom right on your photo .. Pin 3 (top row 3rd from right) is not connected for Manual cars and also Pin 12 (bottom row middle) not connected.

Also the Internet tells me EWS III is different to EWS IIID and that EWS IIID is more like EWS II !!!
 
Matt Barnes said:
Morning!..I have the classic Crank No Start issues after restoring my 1.9 (off the road for 3 years). Car runs fine for 3 seconds in limp mode (ICV and TPS unplugged). My routing around is pointing to the EWS 3D Immobiliser. Mine has the thick Green/Black on Pin 1 and thick Yellow/Black on Pin2. My Green Pin10 sits at 13v output with the key in and drops to around 7v at Position 1. Ties in with my scanner reporting Terminal 30 Ok at key in and Terminal 30 Not Ok at Positions 1 and 2. If I pull Fuse 45 I get Terminal 30 Ok in all positions but obviously now the Immobiliser is in the Disabled state. I get Released status when plugged in, so EWS is reading the key ok. I have pulled the Instrument cluster to rule that out and at rest with the key out, I get only 20mA draw from the battery. Would anyone have a circuit diagram for this model of EWS 3D?... many thanks!
Click to expand...
 
Dont know if this is of any help ?.
IMG_0597.webp


IMG_0598.webp
 
Look at my photo. There's two fat wires. Look at the wiring diagram. The numbers '2.5' on pins 7 and 8 indicate fat wires.

Find a wiring duagram with fat 2.5 wire on pin #1
 
And on my car pin #2 is permanently live. With that I mean the second from top left in this photo

20260810_115849.webp


As the colour suggests, red/yellow. Pin #2

Stop believing google.
 
Duncodin said:
And on my car pin #2 is permanently live. With that I mean the second from top left in this photo

View attachment 368446

As the colour suggests, red/yellow. Pin #2

Stop believing google.
Click to expand...
oooooo now that IS interesting !... never picked up on the 2.5 swg before... that's a cracking spot....... right... I'm going back to Square one and starting from scratch....
 
My car, by the way, is a March 1999 M44.

That EWSIII diagram.matches my EWS 3D Same as yours if I'm not mistaken.

Check the volts on that Red/Yellow wire. Mine is permanently live

Screenshot_20260810-114944_Gallery.webp
 
Duncodin said:
My car, by the way, is a March 1999 M44.

That EWSIII diagram.matches my EWS 3D Same as yours if I'm not mistaken.

Check the volts on that Red/Yellow wire. Mine is permanently live

View attachment 368452
Click to expand...
Thanks @Duncodin I must have completely misread my drawings.... and of course believed the internet !

This is what I have, I'm not sure what difference the serial number make but my pinouts look the same as yours.

1786372546142.webp
 
Another Rabbit hole I went down was, because I'm getting "Terminal 30 Not Ok" in position 1 and 2 was that the DME Relay was not working correctly... (green arrow)

1786373837441.webp


From the wiring diagram this has nothing to do with the EWS, as EWS is fed from Fuse 45 and Fuse 31 and not through the DME Relay !
 
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