P38A Engine Disabled when Fob refused to work

My 2000 4.0 P38 did something today that didn't seem right to me.
Pulled up at the doctors and couldn't lock the car with the fob. This happens form time to time as I need to be within 1 or 2m of the car for the fob to work. But I couldn't get it to work at all this time.

No big deal, I'll just lock it manually.
Returned to car, fob wouldn't unlock the car.
No problem, I opened it manually.
It then wouldn't start with a message of 'Engine Disabled'.

Now, I thought if you don't lock it with the fob, the immobiliser isn't supposed to set. So why did it immobilise?

Anyway, I was lucky. Opened the boot, and with the fob 2cm from where I think the receiver is, it did it's thing and then started just fine.

Got home, and it's back to normal, so assume there are RF gremlins I need to avoid at the docs in future.

If you have a Nanocom, turn off the immobiliser and EKA, then you can use the key blade to lock, unlock and start the car when the need arises. Sounds like the aerial is disconnected from the RF receiver.

Datatek said:

If you have a Nanocom, turn off the immobiliser and EKA, then you can use the key blade to lock, unlock and start the car when the need arises. Sounds like the aerial is disconnected from the RF receiver.

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I haven't got one yet. I've been trying to find a second hand one for a while before biting the bullet and ordering new.
I'll check out the aerial as the distance thing is annoying.

Montyjohn said:

I haven't got one yet. I've been trying to find a second hand one for a while before biting the bullet and ordering new.
I'll check out the aerial as the distance thing is annoying.

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Have a look at the LZ rescue map, there may be someone near you with a Nanocom.

Monty, You cannot remove/ turn off the engine immobilisation. The BECM option just turns off the passive immobilisation (which wd immobilise if you don't put the key in the ignition after 30 seconds). If you're in West London I can help you out on the nano front, but turning off EKA and immobiliser is not the holy grail though (on GEMS at least). You can still be immobilised and if your key is out of synch and the induction loop on your fob is not functioning then you may be stuck. Car will still accept the EKA though, even if that option is disabled int he BECM. It's helpful to keep a second key synched too and/ or a nano in the glove box (which can input the EKA code directly without relying on the microswitches).

I'm in Langley & also have Nanocom for GEMS. License only matters for engine EGU anyway. Any Nanocom can do all the other options.

romanrob said:

Monty, You cannot remove/ turn off the engine immobilisation. The BECM option just turns off the passive immobilisation (which wd immobilise if you don't put the key in the ignition after 30 seconds). If you're in West London I can help you out on the nano front, but turning off EKA and immobiliser is not the holy grail though (on GEMS at least). You can still be immobilised and if your key is out of synch and the induction loop on your fob is not functioning then you may be stuck. Car will still accept the EKA though, even if that option is disabled int he BECM. It's helpful to keep a second key synched too and/ or a nano in the glove box (which can input the EKA code directly without relying on the microswitches).

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That information is certainly incorrect for the diesel and I suspect for the V8 too. If EKA is turned off it will never be asked for and it follows that it will never need to be entered.

I didn't say the EKA was ASKED for if EKA is off, - I said that the car will still ACCEPT it. I have had both the EKA and Immobiliser options turned off for many years now, and vividly remember being stuck at a BP station a few months ago, in the freezing cold with no nano and having to input the EKA code via the door to get rid of an engine immobilised message. The rear release button on the tailgate was semi frozen and not returning properly and I suspect that was confusing things.
In the past i deliberately immobilised the car to show that i could remobilise with the nano using the eka, even if the eka was disabled... the BP incident was the first time i had to re-mobilise via the door method.

romanrob said:

I didn't say the EKA was ASKED for if EKA is off, - I said that the car will still ACCEPT it. I have had both the EKA and Immobiliser options turned off for many years now, and vividly remember being stuck at a BP station a few months ago, in the freezing cold with no nano and having to input the EKA code via the door to get rid of an engine immobilised message. The rear release button on the tailgate was semi frozen and not returning properly and I suspect that was confusing things.
In the past i deliberately immobilised the car to show that i could remobilise with the nano using the eka, even if the eka was disabled... the BP incident was the first time i had to re-mobilise via the door method.

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That is hard to believe. With EKA off the subroutine that deals with it is bypassed in the BECM. However with both EKA and immobiliser off, it is still possible to get the engine immobilised message, but a simple lock/unlock with the key clears it. Immobilisation is a function of the engine ECU, not the BECM, but it is the BECM that provides the re-mobilisation code.

Believe it or not DT, it happened... to a car that had never immobilised of its own accord before, other than one time when I left the lights on : o). The fact is the car will still accept the EKA, with the becm option disabled - which as i explained i proved in controlled conditions via Nano, and i just used in anger via the door lock. Not sure what else i can do to convince you - you're welcome to drop by next time you're in the UK and I'll show you.

romanrob said:

Believe it or not DT, it happened... to a car that had never immobilised of its own accord before, other than one time when I left the lights on : o). The fact is the car will still accept the EKA, with the becm option disabled - which as i explained i proved in controlled conditions via Nano, and i just used in anger via the door lock. Not sure what else i can do to convince you - you're welcome to drop by next time you're in the UK and I'll show you.

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Not all firmware levels of the the BECM allow the EKA to be entered via diagnostics.
Did you have the EKA message on the dash?
All diesels immobilise when the ignition is turned off, it's an automatic function of the engine ECU. I suspect the same applies to the V8.

It's my understanding that the immobiliser cannot be fully turned off. So if you lock the car with the fob and then unlock it with the key because your fob has stopped working you will have an immobilised car. If the fob doesn't work and you don't know your EKA you are screwed.

Gord Wedman said:

It's my understanding that the immobiliser cannot be fully turned off. So if you lock the car with the fob and then unlock it with the key because your fob has stopped working you will have an immobilised car. If the fob doesn't work and you don't know your EKA you are screwed.

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Correct, the immobiliser cannot be turned off as it's a function of the engine ECU, but with immobiliser turned off in the BECM, the BECM automatically sends the mobilisation code when starting the car.
As you say, if you lock with the FOB and then unlock with the key you will get the engine immobilised message, however if EKA is also turned off, a simple lock/unlock cycle with the key will clear it. This happened to me a week ago when the FOB decided to stop working at the supermarket so I know it works.