Hello folks,

Last night my 1996 P38 suddenly decided to stop responding to the key fob when trying to lock it.

This morning I had to enter the EAK code to start it.

On arrival at work it again refused to respond to my attempts at locking it on the fob.

The LED in the key flashes on pressing the buttons and the batteries aren't very old, though are not Duracell.

In the past few days the vehicle has been randomly 'unlocking' itself whilst I've been sat in it but whilst the key was out of the ignition barrel (after getting in or before getting out, I don't tend to just sit in it no matter how nice it is in there).

A few months ago I replaced the security receiver filter thingy with one from a later vehicle.

Before I go hunting through the interweb does anyone know of anything simple/obvious to check? Are these recognized symptoms of something with a known easy and cheap/free fix?

The vehicle is usually trouble free and reliable.

Cheers,

Smiler.

Have you, or your neighbours, got a nice new 433MHz radiating toy for Christmas? Weather Station, router, smoke alarms, burglar alarm, door opener, that sort of thing?
Did you fit a 3rd Gen receiver, or 2nd Gen? The one on the right in pic is the only type that is 99% immune to external interference

Did you ever get round to buying a Nano? You can use it to reset/ clear the RF memory:

Read RF memory: This will confirm if the BECM has received a valid radio frequency (RF)
transmission since it was reset with the clear RF memory function. Although a key fob
may transmit it may not be sending the same Fob code as that stored in the BECM. This
test confirms that the correct fob signal has been received.

Clear RF memory: To be used in conjunction with the READ RFMEMORY function. This
resets the memory, which stays reset until a valid fob code has been received by the
BECM. These then stay set until reset with this function.

Morning, and Happy New Year. :)

It was a second generation module.

As far as I am aware, no new toys in the neighbourhood.

However, I do have a suspicion. I had noticed that occasionally the dashboard would claim that the key was still in the ignition. I am wondering if the microswitch has become gummed up and has now stuck making the vehicle think that the key is still in the ignition, hence the refusal to lock.

Oh, and no, I haven't got a Nano yet. It's on the wish list but so are brake discs, a satnav/headunit thingy and a lot of Scimitar parts...

If it is an auto then the gear selection indication by park, should light up when the BECM is activated.

When its dark outside and the car is locked, go out and see if pressing the buttons on the key cause the light to wake up. This means the BECM has received a code but doesn't know what to do with it. It could be a BECM fault or just requires syncing.

That little key switch can cause all sorts of issues. A good flush out with electrical contact cleaner, flicking the flap while doing it, followed by some graphite should do the trick.
Maybe (and I haven't tested my theory- it's only a guess) the electronics are smart enough to not allow locking if the ignition key is still in the car?

Ah, thanks for the tip regarding the 'Park' indication. I shall remember to look for that in future.

My Rover 75 I had previously wouldn't allow me to lock it whilst the key was in the ignition and the engine running (meaning I couldn't leave it out in the cold to defrost itself). Though I never try'd with the engine off.

Can't try it with the P38 as I only have the one key.

Yup the electronics are smart enough to stop you locking the car if it thinks the key is still in it. Key detection microswitch actuator on mine is a bit sticky and if it doesn't go over when the key is removed the car won't lock. Usually hear it if it doesn't go. Pushing the key back in and pulling out sharply fixes it. Much louder clunk when fixing.

Clive

Couldn't distinguish whether the Park indicator was doing anything but had to use the EKA code again.

Happened to be going to the main dealers. On arrival in the carpark amongst the shiny new (how on earth can you call that a -) Range Rovers she behaved herself again. Locked on the fob unlocked on the fob and started straight away.

Lost sync then!

Better then mine, will not reset mine, replaced case and battery and nothing at all. Its now broken in the garden and Eleanor is doing her best to rock every think around. No way i am going under my p38 on axle stands in this wind to look at the rear diff and fit and remover prop-shafts.

Smiler wrote:

Happened to be going to the main dealers. On arrival in the carpark amongst the shiny new (how on earth can you call that a -) Range Rovers she behaved herself again. Locked on the fob unlocked on the fob and started straight away.

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Aside from the key switch, are you sure it's not RF interference Smiler?
It's a classic problem- fob not working, move car (away from source of interference), fob works.
Has your receiver had the snip- aerial wire cut? If not, might be worth doing. Reduces the range the fob works at significantly, but also reduces the spurious RF problem.

Rather than cut the aerial wire could I not just unplug it?

Yes, single blue wire to the etched aerial on the rest window. Just unplug it.

NOOO cut the red one or is the yellow one??? Its not bomb disposal, yes just pull the wire. Its what I did.

Cool, next time I'm in there it will be getting neutered...

The fob should still work you'll just need to be nearer the car for it to pick up the signal. However that also means any other stray signal will need to be that much nearer too.

I find mine with no antenna requires the fob to be right beside the rear window for solid functionality. The range is so limited its very difficult to resync the key too, as the range from the door lock to the receiver is right on the limits.

I tend to just use the key and unlock manually.

The (new) battery door on my key is also a bit loose, and while in pocket will often rotate a bit. Not enough to pop open, but presumably enough to move the contacts inside and disconnect the battery. I really should get a second key for it, but it seems thats near impossible on these cars.

I'd also like a third gen receiver so i could reconnect the antenna and alleviate the range issue, but i'm not paying dealer money for one, and the lack of external identifiers means its not easy to buy a used one.