P38A Remote not locking (but does unlock)

Dear enlightened forum members ;-)
Does anyone know if there is a fault condition whereby the remote fob will not lock the car?
The LED on the remote flashes for both lock and unlock, and will unlock the car (most of the time).
The batteries in the remote are new and the 12V car battery is good / fully charged.
When locked by the key, all doors & tailgate are locked as expected - nothing comes up on the display, and the alarm LED flashes.
As a side note, I am also having no luck entering the EKA (since I stupidly dissconected the battery without another 12V source attached!) - but the car will start (eventually) after "press remote key" shows on the display: could the two be connected?
Tried the key re-sync - no difference (but this MY should have the 'easy re-sync' anyway?)

2000 MY 4.6L 30th Anniversary Model P38A

Some times one of my fobs wont lock. I find pressing the unlock button then lock button within 5 secs it locks OK Worth a try for nowt

Dodgy drivers door lock micro switches stopped the FOB working as it should on one of mine. I can't work out why that should be but replacing the micro switches has cured the problem.

Zaphodbb said:

Dear enlightened forum members ;-)
Does anyone know if there is a fault condition whereby the remote fob will not lock the car?
The LED on the remote flashes for both lock and unlock, and will unlock the car (most of the time).
The batteries in the remote are new and the 12V car battery is good / fully charged.
When locked by the key, all doors & tailgate are locked as expected - nothing comes up on the display, and the alarm LED flashes.
As a side note, I am also having no luck entering the EKA (since I stupidly dissconected the battery without another 12V source attached!) - but the car will start (eventually) after "press remote key" shows on the display: could the two be connected?
Tried the key re-sync - no difference (but this MY should have the 'easy re-sync' anyway?)

2000 MY 4.6L 30th Anniversary Model P38A

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Fob might need syncing. I think your should sync if inserted in the ignition within 30 seconds of opening but either the RF receiver might be unplugged or the coil by the ignition might be acting up. You could try the manual sync procedure from the manual.

Sometimes it won't sync without opening with the other keyfob first or clearing the RF memory using diag.

When I bought my P38 (2000 my v8), it came with 3 keys, only key 3 worked, I put 1&2 in a drawer and forgot about em,
then one day, about a year later, I bought 2 repair kits as the buttons on em were non existant and the battery covers were
chewed to buggery, after installing all the parts, unlocked with key 3, then used key 1, it started and, the seat re-adjusted,
switched off, shut and locked it, using the fob, then ulocked it, ok I thought key 1 is fine, key 2 would start it but, not lock/unlock
I just put it down to, the fob being knackered on the lock/unlock side.

Grrrrrr said:

Fob might need syncing. I think your should sync if inserted in the ignition within 30 seconds of opening but either the RF receiver might be unplugged or the coil by the ignition might be acting up. You could try the manual sync procedure from the manual.

Sometimes it won't sync without opening with the other keyfob first or clearing the RF memory using diag.

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It cannot be a sync problem as the FOB will unlock the car.

Could it be RF interference ? "and will unlock the car (most of the time)." implies that something is blocking that sometimes as well.

pwood999 said:

Could it be RF interference ? "and will unlock the car (most of the time)." implies that something is blocking that sometimes as well.

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+1 on that.

Or the RF receiver is unplugged and when you're close enough to the rear quarterlight it works but further away or with interference it doesn't. This would also effect the "lazy" sync from the ignition. The fact the key works both ways in the lock kind of points at fob buttons or receiver.

Checking BECM for valid or invalid code received might give an indication. Not sure if 433Mhz interference will cause invalid code, but it will show if fob is received correctly.

pwood999 said:

Checking BECM for valid or invalid code received might give an indication. Not sure if 433Mhz interference will cause invalid code, but it will show if fob is received correctly.

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433Mhz signals will scramble the FOB data so an invalid code is likely.

If the vehicle unlocks off the fob, but refuses to lock, check the ignition barrel isn't sticking. If the ignition thinks the key is still in there the car won't lock.
Check the display isn't saying "key in Ignition" & if so, give it a tap underneath. This should solve the problem.

Wow! - thank you all that have replied.
Update:
I've swapped the drivers lock for one from another working P38 - and metered thorough the one that came out: micro switches are working as expected, but I wonder if the 'arm' might need a tweak to the length - will look again at this.
The fob has been synched but as Datatek mentioned - it unlocks so was 'in sync' anyway (but sometimes needs several presses to unlock - and, there is a delay between pressing the button and the car unlocking).
No 'key inserted' messages when the key isn't inserted - so I don't believe a sticking barrel is the reason Rick, but I will look further int this just in case.
The aerial for the RF received is connected, and I've tried swapped the RF receiver for a known good one (and used my one in the other RR) - both work in the other P38, but perform the same in mine (as per fault).

It would be handy if I had a second key fob, but as a lot of the P38's of this age, it only came with one.

It's really odd - hence my Q if there was a (known) fault condition that could cause this

Zaphodbb said:

Wow! - thank you all that have replied.
Update:
I've swapped the drivers lock for one from another working P38 - and metered thorough the one that came out: micro switches are working as expected, but I wonder if the 'arm' might need a tweak to the length - will look again at this.
The fob has been synched but as Datatek mentioned - it unlocks so was 'in sync' anyway (but sometimes needs several presses to unlock - and, there is a delay between pressing the button and the car unlocking).
No 'key inserted' messages when the key isn't inserted - so I don't believe a sticking barrel is the reason Rick, but I will look further int this just in case.
The aerial for the RF received is connected, and I've tried swapped the RF receiver for a known good one (and used my one in the other RR) - both work in the other P38, but perform the same in mine (as per fault).

It would be handy if I had a second key fob, but as a lot of the P38's of this age, it only came with one.

It's really odd - hence my Q if there was a (known) fault condition that could cause this

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You could try swapping the out station in the drivers door, The one in the passenger door is the same.

Thank you to all that have replied - no luck so far, but I will try the outstation tomorrow as Datatek suggests as I will be replacing the water shedder (completely ripped to pieces by some idiot, not just cut).
I'm now pretty sure the fob itself is somehow faulty.

Zaphodbb said:

Thank you to all that have replied - no luck so far, but I will try the outstation tomorrow as Datatek suggests as I will be replacing the water shedder (completely ripped to pieces by some idiot, not just cut).
I'm now pretty sure the fob itself is somehow faulty.

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I have recently discovered that dodgy drivers door lock micro switches can also cause this problem.

Datatek said:

I have recently discovered that dodgy drivers door lock micro switches can also cause this problem.

Click to expand...

+1 on this. My project P38 would not lock the passenger door properly. Turned out the CDL switch was intermittent, so the BECM though the door was already locked, and didn't operate the motor. Replaced microswitches & all working now. The problem was actually the little button on the microswitch was worn so the level would not operate it correctly.

Also, I know for sure there's interference near my house somewhere, which shows on my analyser every 30 seconds or so. Due to this, the car often doesn't lock on first press of the fob. Another single press 10 seconds later & car locks !! Strangely unlocking is more reliable ??

Sorry - no progress as life has got in the way (not to mention the cold / snow - I'm working outside). I have also been tackleing the heater 'O' rings in parallel to the lock issues, and found the matrix to also be faulty (Audi matrix now fitted with 20cm(ish) long, 19mm ISD silicone hoses & 32mm VW constant compression clamps attached to the Ali pipes after shortening them). I also found water was getting in from the intake vents / flaps - after a lot of searching on the subject and liberal application of grease on the rubber parts and SikaFlex around the plastic screw fixings & grommets, I think this is now fixed.
So, the original lock fault has taken a back seat...

Tried to unlock the RR a couple of days ago - flat battery (old battery & very cold) so put it on charge using my Ctec 7000 on 14.7V to try and liven it up. Went to unlock it today and the lock motors sounded weak and it didn't unlock (Ctec still connected) - after unlocking with the key, I noticed a horrible smell (bit like TCP antiseptic) when I open the door. This appears to be coming from the BECM: do you think 14.7V instead of 14.4V would have damaged anything? Battery now disconnected (I'll deal with the consequences later). I also noticed that the suspension wasn't auto levelling (not clicking) - wonder if the two are connected?

I hope to get the dash re-assembled later this week if it stays dry - I'll see then if it still works (fingers crossed).

Zaphodbb said:

Sorry - no progress as life has got in the way (not to mention the cold / snow - I'm working outside). I have also been tackleing the heater 'O' rings in parallel to the lock issues, and found the matrix to also be faulty (Audi matrix now fitted with 20cm(ish) long, 19mm ISD silicone hoses & 32mm VW constant compression clamps attached to the Ali pipes after shortening them). I also found water was getting in from the intake vents / flaps - after a lot of searching on the subject and liberal application of grease on the rubber parts and SikaFlex around the plastic screw fixings & grommets, I think this is now fixed.
So, the original lock fault has taken a back seat...

Tried to unlock the RR a couple of days ago - flat battery (old battery & very cold) so put it on charge using my Ctec 7000 on 14.7V to try and liven it up. Went to unlock it today and the lock motors sounded weak and it didn't unlock (Ctec still connected) - after unlocking with the key, I noticed a horrible smell (bit like TCP antiseptic) when I open the door. This appears to be coming from the BECM: do you think 14.7V instead of 14.4V would have damaged anything? Battery now disconnected (I'll deal with the consequences later). I also noticed that the suspension wasn't auto levelling (not clicking) - wonder if the two are connected?

I hope to get the dash re-assembled later this week if it stays dry - I'll see then if it still works (fingers crossed).

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I wouldn't have thought 14.7V would be too much, although I would try to keep it between 13.8V and 14.5V.

Doesn't smell good! The new rubber pipes on the matrix wkill smell for quite a few weeks after fitting.

Zaphodbb said:

Sorry - no progress as life has got in the way (not to mention the cold / snow - I'm working outside). I have also been tackleing the heater 'O' rings in parallel to the lock issues, and found the matrix to also be faulty (Audi matrix now fitted with 20cm(ish) long, 19mm ISD silicone hoses & 32mm VW constant compression clamps attached to the Ali pipes after shortening them). I also found water was getting in from the intake vents / flaps - after a lot of searching on the subject and liberal application of grease on the rubber parts and SikaFlex around the plastic screw fixings & grommets, I think this is now fixed.
So, the original lock fault has taken a back seat...

Tried to unlock the RR a couple of days ago - flat battery (old battery & very cold) so put it on charge using my Ctec 7000 on 14.7V to try and liven it up. Went to unlock it today and the lock motors sounded weak and it didn't unlock (Ctec still connected) - after unlocking with the key, I noticed a horrible smell (bit like TCP antiseptic) when I open the door. This appears to be coming from the BECM: do you think 14.7V instead of 14.4V would have damaged anything? Battery now disconnected (I'll deal with the consequences later). I also noticed that the suspension wasn't auto levelling (not clicking) - wonder if the two are connected?

I hope to get the dash re-assembled later this week if it stays dry - I'll see then if it still works (fingers crossed).

Click to expand...

14.7 volts will not harm the BECM, my alternators go to to 14.8 if the battery is low after starting.
Without a good battery, you are on a hiding to nothing, these cars need lots of power.

Hi All,
Well, something isn't right, it isn't totally knackered, but the rear doors no longer unlock with the key (clicking noises), and the engine is showing as disabled in the binnacle display and no amount of fob button pressing whilst in the ignition will clear it. I don't seem to be able to unlock via the remote now either. Not yet tried the door EKA input to clear the engine disable. Oh, and the interior headlining lights no longer work, but the door puddle lights and centre console light do, but they stay on all the time even if the doors are locked, so I've disconnected the battery for now.
One thing I forgot that I did while tackling the heater matrix (and later undid) was to plug the alarm back in after realising someone had unplugged it - seemed OK when I did it, but later found the car was making weird clicking noises (from the alarm) so unplugged it again: I wonder if that has affected the BECM (clutching at straws).

A new question (and assuming the BECM is now knackered) - I have a 2001 4.0 HSE donor car with a working BECM (insurance write-off due to vandalism) - will this work in the 2000 4.6l 30th Anniversary if I swap over the BECM and instrument binnacle*? The cars are a similar spec, but I noticed that the 2001 HSE has separate amplifier modules in the doors, whereas the 2000 4.6L 30th model has the large amplifier in the back. Do I (and can I) also swap over the Thor engine ECU (as I think the 2001 4.0l has has a mod to stop EKA/Engine disable happening).
Sorry for so many questions - getting frustrated as I've hardly had a chance to use it since buying it.

*if this works I'll change the dials over later as the 30th model has a green background rather than black.