E34 Immobilizer Issue...

[TheRev]

Morning all,

I'm having an issue with my e34 since last week. She kept cutting out as I was driving and eventually wouldn't re-start.
Checked for fuel and spark, had neither. Power-probed the fuel pump and still nothing, replaced the fuel pump and still no joy. Eventually got her plugged into diagnostics which gave me a "Key transponder 2" fault. So I thought since I was using the second key (no LED in the key) it was the key at fault. Dug out the first key with the LED, still no joy. She starts intermittently, but I can't trust she won't die randomly when I'm driving.

Does anybody know the fault finding procedure for immobilizer faults or had a similar issue or any idea on how much a new key runs for an e34?

Hoping someone can help

Kind regards
Helpless carless man

[HealyC]

I'd start off by ordering a wallet key, about 50-60 squid off the dealers. It's literally just a plastic key that will start the car and open the door lock via the barrel.

Tbh ews rarely intermittently give fault, they usually just either start or don't start. What are you reading it with? If you posted the above without mentioning a key I would have said crank sensor fault of some sorts. M50/2 engine?


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[TheRev]

I actually have three of the four original keys an none of them are working at the moment, yet when I went out this morning one of the keys started the car on the fourth attempt, I shut her down and tried again and now she won't start again with any of the three keys. I was using AutoCom which I have here at home. Do I need to send the car in to the dealer's to get a new key? Or can they send me a programmed one from the VIN?

[HealyC]

No need to send it in, it will come programmed, just drop into a dealers with your logbook and photo id to order a key


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[TheRev]

Do you know if the EWSII immobilizer kills the starter, or just fuel and spark? My starter is spinning over but I have no fuel or spark

[HealyC]

Do you know if the EWSII immobilizer kills the starter, or just fuel and spark? My starter is spinning over but I have no fuel or spark

Depends on what's wrong with the Ews, usually if it's a key fault the starter won't go and if it's a wiring/power/ecu fault then it usually allows the starter to spin but won't power up the DME so no start


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[TheRev]

Update...

After some EWSII research, I figured it's not an immobilizer issue.

Today's findings:
Went out to it an hour ago, turned the key and hesitantly, she fired up, ran perfectly and then developed a misfire.
Tried to plug in the diagnostic computer but the interface isn't showing any life from the car, so I did a comparison check with another car and it showed life once connected. Now I used the exact same diagnostic computer last weekend and found the "Key Transponder 2" fault. So it's leading me to think it's an ECU issue or possibly a wiring issue to the ECU??

[HealyC]

Is there an aftermarket alarm on the car of some sorts?


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[TheRev]

Is there an aftermarket alarm on the car of some sorts?


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It did, but it went tits up about two years ago and I removed it.

I noticed that when the engine wouldn't start and I had the diagnostics connected the interface wasn't getting power from the car, so I(my dad while I was working) took the ECU out and opened and it has water stains inside it. Where would be recommended to go for ECU repairs in Dublin?