P38A [Failing to] syncing the key using lock ...

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Grrrrrr

Grrrrrr

Technician, Bodgit & Scarper Ltd
Posts
19,529
Location
Buckinghamshire, UK. ('95 DT)
Hi all,

Having put the engine back together, neither keys will sync. Earlier today I got the Nonocom out and had a play. Tried clearing RF memory - nothing. I even tried triggering the locks with the Nanocom rather than using the key ion the lock but still no joy. Central locking works fine from key, sill button or Nanocom. So, I think I have an issue with at least one microswitch? Using the Nanocom:

If I recall correctly, all switches started at 12V.
Turn to unlock and right microswitch went to GND but stayed at GND even when the key went back to the central position. Is that right?
Turn to lock and the right microswitch goes to 12V and the left microswitch goes to GND.

That behaviour pretty much repeats EXCEPT once the left microswitch has gone to GND it just stays there. Doesn't matter if I turn to unlock (right one goes to GND but left stays on GND). Surely that cannot be right?!
 
All doors unlocked I've got
Right cdl ground
Left cdl ground
Right key switch 12v
Left key switch 12v.
Door locked with key I've got
All the same except right cdl goes to 12v but returns to ground when key returned to the central position.

Hope that helps, can do more testing if that was as much use as a one legged man in an ass kicking contest.
 
Key switch should toggle 0v-12v when turning the key, i.e. 12V with key in centre, and ground when you turn the key. CDL should be 12V when door is locked (switch open), and Ground when door is unlocked.

This way the BECM knows if you are turning the key right or left, and the door locked/unlocked status.
 
There's also this from a thousand years ago... Looks like @DanClarke might have had a similar problem...



Screenshot 2025-02-05 at 16.20.18.png
 
Last edited:
Grrrrrr said:
Hi all,

Having put the engine back together, neither keys will sync. Earlier today I got the Nonocom out and had a play. Tried clearing RF memory - nothing. I even tried triggering the locks with the Nanocom rather than using the key ion the lock but still no joy. Central locking works fine from key, sill button or Nanocom. So, I think I have an issue with at least one microswitch? Using the Nanocom:

If I recall correctly, all switches started at 12V.
Turn to unlock and right microswitch went to GND but stayed at GND even when the key went back to the central position. Is that right?
Turn to lock and the right microswitch goes to 12V and the left microswitch goes to GND.

That behaviour pretty much repeats EXCEPT once the left microswitch has gone to GND it just stays there. Doesn't matter if I turn to unlock (right one goes to GND but left stays on GND). Surely that cannot be right?!
Click to expand...
When my p38 looses sync with the keys, they will not re-sync unless I entered the EKA with the individual key. I've tried other ways people suggest to no avail.

Only issue is, unless it is dry out, it is normally impossible enter the EKA with the key. Using the Nanocom doesn't sync the key, even though you can start the engine and using a key that is sync'd also won't let the other sync. It always comes down to entering the EKA.
 
300bhp/ton said:
When my p38 looses sync with the keys, they will not re-sync unless I entered the EKA with the individual key. I've tried other ways people suggest to no avail.

Only issue is, unless it is dry out, it is normally impossible enter the EKA with the key. Using the Nanocom doesn't sync the key, even though you can start the engine and using a key that is sync'd also won't let the other sync. It always comes down to entering the EKA.
Click to expand...
Entering the EKA should have nothing to do with syncing the FOB. Turning the key to lock/unlock while pressing and holding the appropriate button syncs FOB's so I have no idea why entering the EKA code should sync your FOB's. I suspect there is a problem elsewhere that entering EKA covers up.
 
Well, the mystery deepens.

Went out, re-enabled the immobiliser, wrote settings, cleared RF memory (again), shut down. Went out, pressed the lock button to lock ... and the bloody thing locked. Pressed unlock and it unlocked! No syncing necessary. Tried key #4 and that still doesn't work. Cleared RF memory again. Still #4 not working. Tried syncing procedure: nothing. Fiddled with settings. Cleared RF memory etc etc. Still #4, the newest key with the best battery etc does nothing. Still at least key #2 still works.

I have no idea how old the batteries were in key #2 when I bought the car over 12 years ago.They've never been replaced though as the back is jammed on and won't turn to undo. They are getting weaker than they were; I just hope they don't give out.

Why key #4 isn't playing ball is an utter bl**dy mystery. Why key #2 suddenly started working with no resync required (remember my car is too old to have the coil around the ignition for passive sync) is also a bl**dy mystery.

I'm just glad it is one less job to do and I might get ba rest this weekend!
 
Do you have one of Marty's FoB filters fitted ? Both mine have them, but one refuses to do the auto window close on the fob, but works on the key. The one with a newer filter works fine !! Marty did mention they improved the code over time though.
 
Datatek said:
Entering the EKA should have nothing to do with syncing the FOB. Turning the key to lock/unlock while pressing and holding the appropriate button syncs FOB's so I have no idea why entering the EKA code should sync your FOB's. I suspect there is a problem elsewhere that entering EKA covers up.
Click to expand...
Maybe. All I can say is, entering the EKA has worked maybe a dozen times vs 0 for any other method I've been told about.
 
300bhp/ton said:
Just to clarify. Enter the EkA with the key not the Nanocom. That’s what has worked for me.
Click to expand...

Ah. Not sure my door microswitches are working properly so that's probably out. I might have a play with MrGorsky's car or even try to find a battery with enough juice to have a play on the scrapper and see what those switches do.

If Datatek is correct, I wonder if the action of enyering the EKA might brighten up one of your switches that is a bit borderline? Mind you, I doubt it will allow much if it is asking for the EKA.
 
Grrrrrr said:
Ah. Not sure my door microswitches are working properly so that's probably out. I might have a play with MrGorsky's car or even try to find a battery with enough juice to have a play on the scrapper and see what those switches do.

If Datatek is correct, I wonder if the action of enyering the EKA might brighten up one of your switches that is a bit borderline? Mind you, I doubt it will allow much if it is asking for the EKA.
Click to expand...
Manual operation of the lock with the key does tend to move the mechanism differently to operation from the motor, so a micro switch with a worn pip on the actuator may just work from the key but not from the motor.
 
Could be the case. So last time I had an issue I was away on holiday. Parked up in the evening at the hotel and key worked fine. Next morning it didn’t work! Fortunately had the 2nd key with me. A number of weeks later when it was nice and dry out. I entered the EKA with the non working key and hey presto it worked again. But there car wasn’t disabled or anything. The other key would have worked perfectly with it.

I know there is micro switch issue in the door, hence unable to enter the EKa with a key if cold and damp out. But you also don’t press any remote fob keys entering the EKA. So I assume the syncing is down to the key rather than the door.

Btw after entering the EkA I always immediately start the vehicle with the key. That might also help. However if I’d unlocked the car with the working fob and then started it with the non working key it still wouldn’t have synced. On my p38 it always comes back to the EKa.
 
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