I have a 1999 Toyota 4Runner Limited. There is an issue with the door locks which I have been told is the body control module but when I ask my local toyota dealer I get that blank stare from the guys. The locks will open fine but will not lock the doors using the fob and also using the lock switch. If I use direct voltage to the lock it works in both directions. The body control module for the limited is no longer available but is still available for lower models. But if you can shed some light on this issue before i put out 300 bucks would be greatly appreciated. If you know the answer you will be crowned the king of toyota mechanics.
You should be able to tell if the Back Door ECU is receiving the Lock Signal from the FOB if the parking lights flash once when you press the Lock button. (They flash twice when you press Unlock)
Maybe troubleshoot the manual part of the system.
Is the Body ECU getting the Ground signal input on terminals L1 or L2 from the Lock Switch or Door Key Switch to request the Body ECU to output Battery Voltage for 0.2 seconds to Body ECU Terminal ACT+(14) and is the Body ECU also providing a Ground through Body ECU Terminal ACT-(15) and Body ECU Terminal ACTD(23) during the "door lock request"?
If you know the answer you will be ...
Nobody magically knows the answer. You need to perform troubleshooting to locate the cause. You've already eliminated the locks themselves, which is good.
before spending that kind of money, I would make sure that the BCM is definitely the problem, and that I have eliminated everything else. The start of any troubleshooting should always be a wiring diagram and multimeter. Next I would measure to see if the BCM is (1) receiving the lock signal from the remote or switch and (2) giving the signal to lock the doors. Because if you don't positively locate the cause and start replacing parts, you'll be back to square one and $300 poorer.
Yes already did that!
ok. what did you find out?
problem is I don't and Can't get the wiring diagram for the BCM. If you got one I can deal with the module.
it's a 24yo very common vehicle. I'm sure they're somewhere on the internet. They'll also be in Haynes repair manuals, or at your local public library.
Apparently, this Module has the antitheft starter lock out which also does not let you lock the doors. This is why it is discontinued.