Having a problem with the '93 XJS electronic locking system I can lock the door manually from inside the car and also do the same outside the car. I can also open the car with a key but not lock it with the key.
Using the Fob I can lock the car but it immediately unlocks. This is the problem it will not stay locked. Occasionally it will lock but wont unlock unless I use a key. Using the Fob the lights will go on and also it will alarm.
I don't know if the control unit has lost its mind or the fob is defective. If it is the control unit, I would appreciate knowing its location in the car.
Thanks up front!
Afterburner

 

Afterburner,

The chances are that it has a weak actuator, ill-adjusted lock rods from the internal lever to the lock or a slight drop of current in the door wiring to the actuator.

This is a why a key-operated action which is acting directly on the lock mechanism works, but not the remote.

I would suggest removing the door card and then:

- checking, undoing, lubricating and reconnecting the wiring plug.
- checking the actuator action when fired by the remote
- checking that the internal levers can move freely without sticking and that the rod actuation linkage to the door lock is correctly tensioned.

There is a very good chance that you can resolve this without spending any money.

Good luck

Paul

 

Paul
Thanks for your input. Lubrication of all locking mechanism is a good idea and maybe the solution. Since all locks are on the same circuit I don't feel that lubrication of any one or all is the solution to my problem. I don't want to pull the door cards unless it is absolutely necessary.
Looking at the schematic of the door circuits I lean more to the Door Lock Control Unit (DLCU) and at best a bad contact with its single ground or at worst some bad transistors. My approach will be to clean the ground and if that doesn't work I will put 12Vts to the locking circuit and if the locks close, I will look to the DLCU.
I should have look at this manual before I posted, but now that I have I will continue the post until I discover the problem and then post the solution.
Do you know where the DLCU is located? I know it is on the right side by the firewall, but is it in the engine compartment or the fender?

 

Hi Afterburner,

I appreciate that you don't want to pull the card but if, as you say, the lock is firing and then reversing, it's nearly always a tight remote internal lever or ill-adjusted rods. In my (albeit limited) experience, I don't think you'd look elsewhere first as you know the lock is firing from the remote. I've not heard of a DLCU failing before, but, as always, I'm sure it's possible. I would however, expect it more likely to fail completely rather than work then reverse the circuit.

Cheers

Paul

 

Went to Kirby Palms book, page 616, and your solution is supported! Good for you! Have to remove both cards and clean and lube assembly. The plus is I don't have to stand on my head to make the repair.
Never did find the DSLU. It's not in the engine compartment. It must be in the right fender or under the dash. I'm betting on the dash. The repair manual has it on page 86-18 and the operation on 86-25. Unfortunately my manual does not have those citations.