P38 Alarm/door buttons query

Hi all,

I recently acquirred a 1998 4.6 HSE.

After parking up recently I used the key to lock ( have heard that using the key occassionaly keeps lock mechanism working ) - single turn to the rear. On my next trip I used the key to unlock,opened the driver door and alarm went off. I put the key in the ignition - message came up "engine disabled - press remote ". I did and it worked- car started fine. Locked the car as before then used the key to unlock,alarm went off,opened door and put the key in. This time pressing the remote did not work. Neither did shutting the door,locking with key and using fob to unlock.
I changed the batteries in the fob - only took a few seconds - still no joy with fob.

I just got the V5 back so will visit a dealer for the EKA.

Query is : does the flashing red LED on the dash go out after unlocking or after opening the door? Also how high should the door buttons pop up after unlocking ? I have not paid attention whilst using the fob - with the key they hardly move at all but the front door opens - could it be the alarm has not been disarmed ? When using the key to lock the side lights do flash.

The car battery was a bit low - lower now after a few days sitting around.

Hope someone can answer my queries.

Regards
Alexander

I have tried a couple of ways described on here to resynch the fob - putting the key in the drivers door etc.
No luck. I did notice the LED on the remote speeds up its flashing after being pressed for more than a couple of seconds - is this significant ?

Regards

try charging the battery

i have two p38's one in daily use
works fine on keys and remote

other is stood and has been for ages 2-3 months occasionally hook a battery to it

both of them open the locks same height whichever method is used

hope this helps

Lock buttons only go up and down about 10mm but can stick or develop faulty actuators. Sounds like you have a combination of low battery power and sticky mechanisms. Two ways of re-synching the key, one for up to about 1998 and one for newer. The older one is more tricky. Put key in lock, press and hold lock button and turn to lock then press unlock button and turn key to the unlock position. Repeat four times switching the thumb to each button as you turn. (Kind of like patting your head and rubbing stomach at the same time!) The method for the newer ones is simply to put it in the ignition switch. The red LED will flash 3 times and that's it - a lot simpler. Try both. The quicker flash on the remote is normal and indicates lazy locking active but that's a whole different story. In short it lets you know you've held the button longer than you need to to lock/ unlock. The dash LED should only flash if the system is armed in some way or the car is immobilised. In normal running it is off.

Thanks for replies.
When using the key : only the drivers door gets unlocked but the button only goes up a couple of millimeteres - does this cause the alarm to stay active ? When I did use the remote all doors opened though I don't recall how high the door buttons were compared to locked.
Any suggestion for sticky mechanisms - apparently WD40 is not recommended ?
Alex

On the subject of resynch - if the car is locked with alarm LED flashing on the dash will resynch via the driver door work ?

Firstly, is it still sub-zero down your way? If so it could just be the internals frozen which unfortunately is common on the P38. If not you need to get the door panel off and free off everything inside. The drivers door lock is the main one for the whole car and specifically controls the tailgate lock too i.e. if you can't get the boot open its most likely the driver's door playing up rather than the tailgate itself! (I digress). Resynching will sort out the led however you need to get the mechanism working through its full movement again. Try leaving the window open and helping the button up with one hand while using the key in the other. WD40 is not really recommended in the ignition but for the mechanical bits inside the door it should be ok. You could use silicon spray on the nylon bushes but best of all a graphite lube is best. Its a dirty dark grey colour though so watch the upholstery, etc. If all else fails a plug in to Test Book will be able to test each and every lock mechanism and door outstation in turn and tell you which if any is faulty electrically.

Hi hippo,

Not sub zero here in London N9 for a few days.
Battery on the car is now discharged - no LED flashing on dash. I have just removed it and put it on charge.
On your car what is the difference in height of the door buttons when locked then unlocked with the key or remote fob ?
I will have a "go" behind the door card - won't be till weekend though.
Bye for now

Alexander

When the buttons are down they are just below the top of the scooped out bit with enough room to stick a finger under to lift manually. When unlocked they go up about a centimetre and sit just above the top ledge. Sounds like you have a jammed or wonky mechanism. Taking the door trim off is easy. Two screws under the pull handle pointing up the way and one in the opening handle escutcheon. Then its a series of press clips all around except the top however you need to take off the little speaker panel at the mirror corner. It pops out with a tweak and there is another screw beneath it. When you lift the card off the top ledge and over the top of the lock button remember to disconnect the speaker plug. Three hands are handy here unless you balance it on your foot! Peel back the gooey rubber insulator and you will see a collection of rods and clips. Give the locks a try as normal before further dismantling as there is the offchance that the button is getting stuck in the channel on the door card. Its actually an easy strip down and gives you a chance to lubricate the window channels and lifters too - with a silicone spray. Be wary when you refit the battery as you could get an alarm going off and you will have to reset all the windows and sunroof too if you have one.

It actually reached 5 degrees up here today at last!! Saves the fingers freezing when working on the RRs.

Hi hippo,

Thanks for that - hope weather is not too bad Sat/Sun !!

Any suggestions for re connecting battery to avoid alarm problems ?

The battery was put in Nov 2006 - I will probably get a new one - the current one fills the battery space - another one like that I reckon. It is a "664" with 95AH and 680 CCA - though higher CCA should be available.

Alexander

That battery is a truck one and more than big enough. You can actually get away with a smaller one like a 069 (or a 250). If you put too high a capacity battery on any car you could run the risk of it never being recharged enough to its whole capacity thereby making it less effective once it settles in. In otherwords it will just act like a smaller one and go off sooner than it should because its not being 'worked' properly. It depends on the state of the alarm when the battery was taken off that matters i.e. whether set or unset. Its just in case it does yelp that you are prepared for it . Don't leave the keys inside with all the doors shut either when you do re-fit it as the central locking could just go "thunk" when power is re-introduced leaving you outside in the warming cold! :doh:

(When removing a battery on a RR it should be done within 17 seconds of the ignition being switched off otherwise the back up alarm, if fitted, will sound) The secret there is to have everything loosened ready to just pull off and switch the ignition on and off, then run round the front and disconnect the terminals. They are fickle cars.

Hi,
The alarm LED was flashing on the dash as the battery ran down - no noise when i took it off as battery was dead. So alarm might sound on refitting ?
Assuming a 120Amp alternator anyone know what is the highest capacity battery that can be properly "serviced" by said alternator? Is battery measured in AH , CCA or both ?

The Ah rating of the battery shows that at (say) 70amp discharge rate it will last one hour. So at 140Amps it would last half an hour. Etc....
The CCA rating shows the maximum current capability of (say) 660Amps.
Tbat is the BATTERY data.
The Alternator figure shows the maximum current the alternator can produce - (say) 65amps.
Now if you have loads of lamps on, the heater and air conn on, for the sake of argument lets say they take 960watts - thats 80 amps.
Now the 65amp alternator can only produce 65amps max, so the load on the battery is going to be 15amps. So it will last about 4.5 hours before the whole lot is as flat as a pancake. By upping the Alt to 100amps, the entite load can be supplied by the alternator and yu wont flatten your battery.

It aint thatcsimples but it gives yu an idea.