Mine's just developed an odd fault. If you turn the key to III all the accessories shut off like you'd expect, but the engine doesn't crank. It's exactly like it thinks it's not in N or P but the dashboard says it's in Park. If I jumper the starter relay, the engine will turn over but there's no spark at the plugs, presumably because it's "too smart" to fire the ignition if it's not actually being started on the key? Although that being said, I thought you could bump start manual V8s, so that kind of makes no sense. The ignition switch seems to deck the appropriate pin on its connector.

It's too dark to really check if all the supply rails are present but that's my next port of call.

Any other thoughts?

Do you have the check engine light when in position 2?

If not, lost sync between becm and engine ecu. GEMS won't crank when sync is lost. A Thor will though.

Is it asking for the EKA? If not, try it anyway.

It's not asking for the EKA, and I don't have a note of that here anyway.

I'm not seeing the engine management light come on, although I can hear the fuel pump start up and run. It seems to have switched and unswitched 12V available at the right pins.

I also notice it doesn't have its alternator light coming on. I did change the alternator recently, although it's worked since then.

Does the battery have a good charge? Cd it be that the alternator has stopped charging properly since you changed it?

Trickle charge overnight, to be sure?

The battery was okay but with spending an hour or so dicking about trying to diagnose what's gone wrong it is now flat. It was charging well when I drove the car yesterday, with the little LED meter thing in the 5V charger adaptor saying 13.7V.

Do the dash warning lights stay on when you try to crank it or do they go out as well as everything else going off? That would be a sign of a flat battery or duff battery connection. But if that was the case the starter wouldn't turn when you jumper the relay. EKA will be the 4 digit number saved in the phonebook on your phone under EKA. If it isn't it should be. Have you got a Nano or are you still blagging one from Miah when you need it?

Yup, I'm planning on taking the BECM round to Miah's so we can pull the contents of the EEPROM. I don't think I ever got a note of the EKA from the previous owner! I checked to see if it had been scribbled in the manual, too. The radio code is there but not the EKA :-/

I'm hoping I can get a shot of Miah's Nano. There's an app called "GEMS ECU Utility" for Android that reckons it can clear the adaptives and resync the immobiliser but while I could get it to connect and do stuff it didn't improve matters any.

You can get a printout with the EKA, radio code, lockset bar code, etc from your local friendly LR dealer in exchange for a look at your V5. You can set EKA to disabled in the BeCM but I'm not sure what it does. If it doesn't need it how do you reset it when the BeCM and ECM lose sync? Or is it that it just doesn't ask for it?. Even if you are entering it with the Nano, you still need to know what it is.

In the absence of Marty.... I did ask him the same question once and the reply wasn't quite what I was expecting and amounted to "best leave it as it is". Sorry, I didn't file away the details - just the instruction :)

If the BECM and GEMS engine ECU have lost sync, the EKA will not fix it. It just won't crank, and you don't get any engine disabled messages etc. The check engine light will simply not light up and that is about the only sign of what is going on.

A nanocom will be needed to sort it.

So what is the fix if that is the case? Is this what the mysterious Security Learn option in the Nano does?

Yes, it aligns the static code in both BECM and GEMS ECU.

The EKA actually has nothing to do with the engine ECU - it is entirely a BECM security function. When the correct EKA is entered, the BECM sends the engine mobilisation code to the engine ECU as it would if the car had been properly un-alarmed etc. But if its sending a code that doesn't match what is in the engine ECU, said engine ECU will just sit there immobilised. So the car appears to be behaving normally - no EKA or disabled message, and the BECM is firing off the mobilisation code - it's just the wrong code.

The Thor has a similar option under Motronic on the nanocom, but in my experience it doesn't work, and you have to go into the engine ECU, make a note of the code, then go back to the BECM and manually enter it. It has been years since I've done it on a GEMS - you might be able to do it manually for those too, or use the security learn.

The Syncmates do the same thing.

Sorry Sloth, forgot you know all this stuff too :)

Certainly sounds like that is Gordon's problem. No Check Engine light, no crank but no immobilised message or request for the EKA.

Something that might help, better/cheaper than SyncMate (but in OZ) !

http://www.labtronx.com.au/labtronx-products/mobi4

That's an interesting wee deelie, I wonder what's under the heatshrink and where it gets fitted? I guess it just sends "immobiliser learn" and then anything at all to the GEMS ECU?

Also interesting that just jagging across the starter relay ought to make it start - mine has no spark. So that answers that question, it ought to be possible to bump start the engine if it's in a manual.

Conclusion: Well that's weird.

I got round to the flat, put the jump leads on, let it charge up a wee bit - door open, key in pocket! - put the key in, turned the ignition on and the alarm went off. Key out, lock, unlock, key in, turn on, chorus of Assorted FAULT BEEP BEEP BEEPs, ALARM TRIGGERED, ALARM TAMPER, IGNITION TAMPER, turned it to start and it fired on the first flick! Like, it's never started that readily before.

Well hell.

As we eventually discovered with mine when it was being hit by a faulty 433 MHz wireless central heating thermostat sending bursts of random data every 15 seconds, that bought on the IGNITION TAMPER warning and I suspect you jumping the starter caused the ALARM TAMPER one too. Next time you are at the flat, take a receiver and see what is on 433.95 or thereabouts in the area.