Immobiliser problems.

[Dualist]

Hi guys,

I hope you some here can help as this problem is starting to drive me insane.
I had the little swimming pool under the passenger seat that fried my immobiliser, I dried it out and the car still starts but doors don't lock and the windows don't work now.
So I brought a secondhand tested immobiliser, ecu, fob with pill and transducer, disconnected the battery, installed the gear and everything worked as it should but for some reason the car won't start. Swapped my transducer and pill and still the same issue, won't start. I spoke to the seller who is a porsche garage and gone through what I did and still engine won't start. They very kindly send out another set for me to try, I fitted this this afternoon and still the same problem, all the electrics work but just won't start.
To see if I'm not going totally mad I changed over to my ecu and immobiliser and car starts no problem but windows and locks still don't work.

Any of you guys know what I'm doing wrong or what else I should be doing when I do a swap over like this.?

Any help is greatly appreciated.

[78F350]

Take a good look at the wires and plugs that connect to the immobilizer box under the seat. There may be corrosion on a connector or a broken wire.

[particlewave]

Adding to what 78F350 said, pay particular attention to:

1 - the black wire
2 - the black wire with yellow stripe
3 - the black wire with red stripe.

These are the transponder coils signal transformer signal wires.

[Dualist]

Ah cool, thanks guys. Everything seems to be ok but I get a no go on the 'start lock' relay. I'll have a look again this afternoon to see if I can frig this to get it started.
If I can then I'll try the other unit to see if it works then send this one back and look at why the transponders aren't playing ball. Think I may have to get the new(ish) immobilisers recoded to the transducers, I hear it's a half hour job if it is.
Thanks.

[philou320]

what model of car?

[Dualist]

2001 S.

I can frig relays to make it run but it's not right, neither of the immobilisers read the pill code right that came with them. So after talking to my local pcar dealer they can supply a new immobiliser for £230, key fob for £115 and half an hours labour (£30) to program it all up (plus mr vat). They will only program new immobilisers not 2nd user ones. With my box installed at least I can drive my car to them and wait.
Never thought a new box would be so cheap, but they did warn me that if it took the ecu out it would have cost another £3000 just for that

[thom4782]

Too bad you don't live in the US. There a shop in Florida that will repair both the ECU and Immobilizer for less than USD $1600. You can find them online at

2000-2004.

Perhaps there is something like this service in the UK.

[Dualist]

Erm.... to repair it is $875 (£573) and to buy a new unit from Porsche is $351 (£230) and to program it is $45 (£30).

[thom4782]

Originally Posted by Dualist

Erm.... to repair it is $875 (£573) and to buy a new unit from Porsche is $351 (£230) and to program it is $45 (£30).

The numbers I quoted included repairing the £3000 ECU. They claim a 100% success rate.