hiloracerboy84

ok, so my mom has a '00 Ltd. 4runner and the keyless entry and door LOCK switches/buttons aren't working. she can unlock the doors with the remote and button on the doors but can't lock the car, except with the key manually. I've tried searching on this but nothing's come up so I'm thinking it's a bad relay or something just preventing the p/l mechanism from working correctly. anyone have this issue or insight on what it might be?

GSGALLANT

My 2002 has no relays in the power lock circuit. Everything is controlled by the body ECU. I just took a quick look at the wiring diagram, and if it's the same as my 2002, nothing except the Body ECU jumps out at me saying that it could be the problem, other than maybe one of the switches or buttons being stuck in a certain position, leading to a continous grounding of a part of the circuit. A multimeter will definitely be your friend to trace this problem.

PS. When you say she can lock the car manually with the key, do you mean when she turns the key in the driver's door lock, just that door locks, or all the doors will lock? How about with the key in the passenger side door lock?

hiloracerboy84

she can turn the key in either driver or pass. door locks and all the doors will lock.

BruceTS

ok it's narrowed down just a bit....... the actuators in the doors are OK

Does your mom have a second remote? if so try that. When the battery in the remote starts going dead, they do weird things as well.

hiloracerboy84

Sorry Bruce - heres whats going on:
pressing the unlock button on the keyless remote unlocks all doors
pressing the lock button on the keyless remote doesn't lock any of the doors
using the unlock button on the door unlocks all doors
using the lock button on the door doesn't lock any of the doors
turning the key in the pass/driver door will unlock all of the doors
turning the key in the pass/driver door will lock only that door

so....if all the doors are unlocked, my mom has to manually go to each door and lock it, but even then the trunk door is still unlocked.

thanks for all the help guys

nieuwendyk-25

You definitely have a electrical issue, probably in one of the door switches (if one is shorting it may stop the all the locks), control unit (or relay if equipped), or the wiring. Question, just to clarify, what if you try to lock from the passenger door switch? Still no locking? What about the rear hatch, will it lock or unlock? And this is factory keyless entry?

There are relays present, but they may be built into a control unit or keyless entry module.

nieuwendyk-25

That should not effect the door switches though....

BruceTS

At the time I answered, I misunderstood his exlpanation of what the problem is. Using the key to lock and unlock is on a different circuit vs the remote, a simple assumption with information given to that point was the remote was malfunctioning. Now he's cleared up the information that now excludes the remote from causing the problem and has narrowed where to search for the problem.


The interior control switch wiring go directly to the body ECU, there is no relays between them and on a separate circuit, but could be on the same as the remote. I have yet to teardown a body ECU and there are no schematics for it's circuitry. Toyota will most likely say it needs replacement........ If your good with electronics, you may try and tear it down, the problem is it's a PITA to work on, it's the assembly that has the interior fuses on it, basically a crap load of separate electronics in one big package.

nieuwendyk-25

Actually Bruce, he contradicted himself in the two posts...he said it would lock all the locks with the key, then later said it would not. That was a little confusing and I think it still leaves the question of a short in the "lock" circuit whether it be in the switch, wiring or in the body ECU.

Bruce, have you opened up the body ECU before? If so, is it possible to see the fuses and if one was blown? If a fuse could be pinpointed are the soldiered on to the board, or are they easily changed?

I do hear the relay clicking on mine (but it may be inside the Body ECU), behind the fuse box, is this the location of the body ECU? I would try this. To rule out a switch issue (which could be possible since they can get wet on rainy days and corrode), disconnect the large plug on the drivers side control unit (door switches). When you do this you will not be able to unlock the doors either from the drivers side. Then try to lock them from the passenger side. If still unable to lock from the passenger side, then put the drivers side back together and do the same on the passenger side (disconnect and try the drivers switch). They work independently of each other but can cancel each other out in certain situations. Just thought this might be worth a try since it is simple and less costly than an ECU.

Good luck!

BruceTS

the fuse box is part of the body ECU, which includes quite a bit of separate unit attached to it. If you ever tried to remove the unit you'd understand what I mean, wire connections everywhere. If a relay is clicking, it's part if the body ECU and that can't be purchased separate, unless you know about electronics. From my experience with other components, they probably have 2 surface mount relays and one of them is malfunctioning or the circuits going to it.