Power Door Lock issue.

[celticbhoy]

Hi everyone,

So I have this extremely frustrating problem with my car’s power door locking system. My car is a 1996 Toyota Avalon XLS, 3.0L V6 1MZ-FE engine.

Basically, while driving my locks would lock and unlock erratically. When I’d shut the car off, it would continue to lock and unlock for a moment before stopping. After the chaos would end, the locks would be inoperative, meaning, the driver and passenger switch wouldn’t work. I don’t have a remote for the locks, never have had one.

Just recently, the unlock function doesn’t work. The doors lock fine, but the unlock button doesn’t work. I disconnected the driver’s master switch and checked that voltage was getting to the lock and unlock connectors, and there is voltage (7.5V) at each connector. So then I tried jumping the two circuits with a test light that was grounded. I supplied ground to the lock connector and the locks locked. Then I supplied ground to the unlock circuit and nothing. It’s difficult finding information about this vehicles power locking system online so I’m not entirely sure where all of the relays are for this, but this vehicle does have theft warning module that clicks whenever I lock the doors. I guess it’s also the door lock ECU or something. I’ve tried wiggling the wires in the door jam while pressing the unlock switch but there’s nothing happening. No clicking sound or anything.

This has been driving me crazy. I need to figure out why the doors will not unlock and what is causing the locks to act so erratically while driving. If anyone can give me a hand, i’d really appreciate it.

Topic

[Joeseph Mama]

Door lock diagrams traditionally look like spaghetti despite the simplicity of their operation. The reason for this is that the driver door lock for example would have to be tied into every other door lock in the vehicle.

So, here is how your door locks are wired up:

Being that the problem you describe affects the entire door lock system, I would suspect a major component. In this case, I would look at the “door lock relay” or even the “theft deterrent and door lock control ECU.”

Attachments:

• toyavlocks1.pdf
• toyavlocks2.pdf

[college man]

see if this helps.

http://www.toyotanation.com/forum/154-1st-generation-1995-1999/452425-1996-avalon-doors-lock-their-own.html

[celticbhoy]

Thanks for the information guys. So it looks like there’s three possibilities (so far).

1. Door Lock Relay could be faulty.

2. The Theft Warning ECU could be faulty.

3. The door lock cylinder switch may be faulty.

I have noticed that when I put the key in the driver’s door, the key fits pretty loosely in the cylinder, whereas it’s a tight fit in the passenger side.

I have located the Theft Warning ECU but have no clue where the Door Lock Relay is located.

[Joeseph Mama]

I can only find a free diagram of a camry online.. but I believe the camry and the avalon were built on the same platform.. so give this a try:

Attachments:

• 99toyavrelays.gif

[celticbhoy]

Thanks for the photo.

Something happened this morning when I first got to my car. Before I started it, I tried the lock/unlock switch and everything was working perfectly. Everytime I unlocked the doors, I would hear a slight rumble coming from the passenger door, and then when I started the car, the unlock switch wouldn’t work anymore, just the lock… this is really sounding like a anti-theft system issue…

[EricTheCarGuy]

It might be the antitheft but I would suspect one of the actuators before I went there. They are a common fail point. You might try unplugging them one at a time to see if the system then begins to operate normally. My prime suspect would be the drivers door lock but since you heard noise coming from the passenger side, you might want to start there. This might also be helpful.

http://www.ericthecarguy.com/faq/solving-automotive-electrical-problems

Good luck and keep us posted.

[celticbhoy]

So the driver side front door’s actuator could control the other door’s actuators? I guess that makes sense since I can unlock all of the car doors by turning the key in the lock to the right twice… or at least I used to be able to do that before this problem showed up. Thanks for the suggestion.

[Author]

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