Front Door Central Locking sudden fault

Hmmm . . .thought things were going too well.

Finally got my dash back together, and got the air-con re-gassed. Excellent job by my MOT guy, and now have cool air & no handbook symbol.

BUT when I got home both front doors will not lock or unlock using the remote. Key works fine, as long as I unlock with the Fob first to un-set the alarm. Either left or right buttons lock & unlock the rear doors ok, but not the other front.

I replaced both latches in Dec 2013, so hopefully they've not failed again. Guess it's time to have the door cards off & check them. Already checked fuses.

Pete

You checked the white block connectors, floor level "A" posts?

Not checked anything yet . . .too dark !!

But yes I will be checking C301 & C302 where the wires go through to RH door, plus the corresponding connectors on the other side. The usual white connectors behind RH kick panel don't seem to feed the doors.

Strange that both front doors stopped working at the same time ?

pwood999 said:

Not checked anything yet . . .too dark !!

But yes I will be checking C301 & C302 where the wires go through to RH door, plus the corresponding connectors on the other side. The usual white connectors behind RH kick panel don't seem to feed the doors.

Strange that both front doors stopped working at the same time ?

Click to expand...

Last time both my front's stopped they had burnt out, the old R/F problem

just been out in the dark to check BECM is actually going to sleep. LED in Park position goes out after two mins approx. so hopefully stays asleep.

Maybe I should borrow a spectrum analyser from work & check the stray RF . . . . and then kill the neighbours if required.

Update on this one. . . . .

Extracted the front drivers door lock today to check it out. Nothing wrong with wiring, no corrosion, etc. Microswitches all working as they should, and lock is physically ok.

So on to bench time to check the motors. Used a small multi-voltage charger as PSU, and set it for 9V to avoid stressing the motors too much. (must check what voltage they really are one day)

• Superlock motor seems to be working ok, spins every time, and very quiet too.
• CL Motor is the issue. It's not burnt out, but instead seems to have intermittent brushes, or contacts. Every so often when disconnecting 9V, it stops in a position where it will not start again. Moving the spindle a few degrees, enables it to start again. Sprayed it with contact cleaner, and blew it out with compresses air, but no improvement.

As I already checked yesterday that the BECM is falling asleep when it should, I have now checked for Fob Receiver Code faults on Nanocom. Cleared old errors, and will check again tomorrow for any invalid codes received. This should tell me whether the BECM is being woken up by stray RF.

Next jobs are to check the passenger door lock, and locate replacements. Given that I replaced both in Dec from same supplier, they could easily have the lightbulb effect and fail together !! Interestingly I found this thread on Rangerovers.net P38 lock/latch alternatives ? about the MGF locks that seem to be identical to the P38 locks. Internals look the same, even including the superlock. Externally they have the same lever attachments. Main differences are quantity available on Fleabay, and the price !! I wonder what the new price will be ?

and in case anyone is wondering, the motor wiring is embedded into the plastic mounting, so looks impossible to replace just the DC motors

Pete

Replaced the door looks in 2013 so should be ok.

I know people that replaced their locks last week & have failed already.

Rick-the-Pick said:

Replaced the door looks in 2013 so should be ok.

I know people that replaced their locks last week & have failed already.

Click to expand...

+1, my first replacements lasted a month

Checked the BECM this morning, and zero false codes received from RF. Hopefully this means no local interference, but I'm gonna check & maybe replace the receiver anyway. Will also check in all my usual parking spots like work, parents house, etc. !!

Ordered a pair of MGF lock motors to see whether they are identical.

Also wondering about these motors 2 pcs Universal Long Shaft Car Door Lock Actuator Motor Repair | eBay which look like the correct shaft length. The wiring could easily be routed around the outside of the LR motor moulding.

Pete

pwood999 said:

Checked the BECM this morning, and zero false codes received from RF. Hopefully this means no local interference, but I'm gonna check & maybe replace the receiver anyway. Will also check in all my usual parking spots like work, parents house, etc. !!

Ordered a pair of MGF lock motors to see whether they are identical.

Also wondering about these motors 2 pcs Universal Long Shaft Car Door Lock Actuator Motor Repair | eBay which look like the correct shaft length. The wiring could easily be routed around the outside of the LR motor moulding.

Pete

Click to expand...

The problem is pulling the cog off the shaft and pressing it on to the new one. The motor in the R/R is the same as used in the VW polo and probably other marks. Good luck and keep us posted, I have a box of locks with burnt out motors awaiting refurb. I did a lot of research into manufactures in China and Vietnam without success. All the motors in my locks were made in Vietnam.Looking at the photo the motor clips in to the lock so no need for routing wiring

There is a special tool for the job !!

Scalextric Gear Puller for Slot Cars Hardly Used | eBay

Or maybe I will make one of these:

Received my MGF locks today.

• Driver side lock is identical to P38 lock. Only mod required was the black single wire connection for the micro-switches, but that was because my P38 has previously been modified from the original connector.
• Passenger side is "almost" the same but lacks the 2nd micro switch, so doesn't quite work.
• MGF locks also have the small super lock motor.

So for the passenger side I dismantled both locks to see if the microswitches could be swapped. This could be done, but would require drilling small holes for the mounting lugs.

So then I decided to remove & inspect the intermittent motor on the original lock. What I found is they actually unplug from the plastic mount . . . . and guess what . . the MGF motor is definitely identical to the P38 one. Plugged in the MGF motor, and now the old lock works again.

So, fully fixed for £35

Guess which is P38 and MGF ?


Pete

Good info that Pete. May save the hard pressed P38 owners a few bob.

I spent bl**dy ages trying to track down the replacement motors. Mabuchi or whatever with extra long shafts. Came up with diddly squat but the MGF motors work OK. Or the early ones at least.

pwood999 said:

Received my MGF locks today.

• Driver side lock is identical to P38 lock. Only mod required was the black single wire connection for the micro-switches, but that was because my P38 has previously been modified from the original connector.
• Passenger side is "almost" the same but lacks the 2nd micro switch, so doesn't quite work.
• MGF locks also have the small super lock motor.

So for the passenger side I dismantled both locks to see if the microswitches could be swapped. This could be done, but would require drilling small holes for the mounting lugs.

So then I decided to remove & inspect the intermittent motor on the original lock. What I found is they actually unplug from the plastic mount . . . . and guess what . . the MGF motor is definitely identical to the P38 one. Plugged in the MGF motor, and now the old lock works again.

So, fully fixed for £35

Guess which is P38 and MGF ?


Pete

Click to expand...

Told you they just plugged in ( see post 10) Well done, good info.