93 Camry LE door locks goofy after ECU replaced

[Monguse]

I just had a mechanic replace the engine control unit in a '93 Camry LE. Now when I try to lock the doors with the electronic door lock, it locks and unlocks all 4 doors very fast and sometimes clicks them on and off all by itself and will not stay locked unless done manually for each knob. The first time it happened, right out of the shop, I manually locked all but the drivers-side door and tried the drivers side door-lock switch several times and it worked fine then. But since then, no luck.

Can this problem be directly related to the newly installed used ECU? Does the ECU control the door locks? In examining the fuse box under the hood, the fuse diagram on the inside of the lid did not indicate that any of those fuses were for the door locking circuitry. Does anyone know where the door lock fuse is? The wiring at the door hinges is encased in some kind of rubbery sheath so I haven't tried to examine the condition of those wires. Anyone have any answers or ideas? The mechanic who installed the used ECU had originally stated that the old ECU would be rebuilt for $400, with the total bill for the trouble shooting (car would die at idle) and repair being $800. I told him I would find an ECU for a lot less and I did. Now he claims that the door lock problem is caused by the computer. Is this possible?

Thanks

[dc_98_cam]

... Seeing quite a few comments regarding deterioration of the wires going through the front door ... probably the rubber encased area you referred to.
... With the driver door open, why not manually agitate or jar the wire bundle and see if anything unusual happens. ...However, not completely sure that locking system is activated with any door open. ....

[Monguse]

Thanks, I'll give it a try.

[Monguse]

Oddly enough, went out to check the door locks and they're working again without my having done anything except leaving the car sitting in the rain all night. So this seems to be an intermittent problem at this point. Also prior to the mechanic installing the new ECU, the front seat passenger window wouldn't work either up or down. Now it works for down, but won't go up.

Hmmm?

[eddie926]

On my '95, the lock switch on the driver's door works fine if the door is closed, but if the door is open it won't work. With the door open, if I massage the wiring at the door hinge that you describe, I can get the switch to work. My Toyota mechanic says it's pretty common for that wiring to break in the driver's door from being opened and closed so many times. Whether or not that could cause the exact symptoms you describe, I don't know. But, you might try opening that wiring cover up and see if the wires in there are broken.

[toyomoho]

Have never seen the door lock system of a 93 model connected to the ECU in any wiring diagrams. The two systems should be independent.

Check the door wiring as previous posts suggest plus the door switches. A bad switch can also cause the locking system to go off on its own. If the mechanic states it is the ECU, he or she needs to look at the wiring diagram.

There is also a fuse panel behind the drivers left side ash tray, lower part of dash where you left knee would be.

[Monguse]

Thanks for your info.

I'm no mechanic and I appreciate your appraisal of my problem. Is it possible that the mechanic could have screwed something up when he replaced the ECM?

[renmike]

There's always the chance that when the mechanic was replacing the ECU that they moved some wires around to get the unit in and/or out, and in that case pinched a wire or did something that would make it lose connection. I would take it back to the shop that did the work and have the mechanic recheck what he did up under the glove box, seeings that so many wires are ran around the part of the car.

[Monguse]

Thanks for that advice. I'll give it a try.

Jay