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Central locking nightmare!


TRD3000GT

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OK.

 

Its still broken.

 

So far looked at and replaced......

 

Drivers door, closed electrical switch pack (windows, and lock switches)

 

Looked at Dome ?? fuse in engine bay fuses and seems to be good... but the fact that it unlocks but does not lock would suggest it was not a fuse

 

Alarm system.

 

 

It just seems to be the following. There is NO problem with the unlock on the alarm, keyfob or the switch inside the car...

 

But the lock has completely gone. I have to manually flip the switch inside or close the door with the key!

 

Its a big pain in the ASS!! :angry: :angry: :angry: :angry:

 

I think it could be the central locking motor ?? Anyone know where it is ?

 

Or anyone got any other ideas. ?

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OK,

 

I have 2 key fobs, and my toyota key has a remote lock, unlock .

 

The unlock works on all of them but lock is a no go.

 

The switch in the drivers door works for the unlock but not the lock.

 

( this is the uint I replaced at £ 85 !! and it did not resolve the problem )

 

Im comming to a loss, I hope its not too difficult to fix!

 

If its the lock circut or motor, where do I find these units ?

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So the only way to lock the doors is to manually flip the orange-marked flippy things located in the handle, and you have to do this for both doors, right? Not taking the piss, just being very clear on what does and doesn't work. The fob and the "lock all" button doesn't work. Does putting the key in the lock and turning it successfully lock the car?

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Originally posted by Ian C

So the only way to lock the doors is to manually flip the orange-marked flippy things located in the handle, and you have to do this for both doors, right? Not taking the piss, just being very clear on what does and doesn't work. The fob and the "lock all" button doesn't work.

 

Correct, But I can also lock it manually with the key from outside. Put in door turn... you get the idea

 

:)

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Hmm, well, the circuit diagram is a bit chocolate fireguard as it's for a US spec car and they seem to have a door lock switch for each door rather than one master for both doors at once.

 

So, it's multimeter time for you :) I'd start at the lock-all switch. If you can suss out which pin does what, you should be able to compare the "unlock" circuit with the "lock" one, and I bet you get either no power fed or no ground switched in when you try and lock it. Follow that circuit to power or ground and you'll find a break in it somewhere.

 

If both doors exhibit the same behaviour I'd say it's not the motors.

 

-Ian

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Originally posted by Ian C

Hmm, well, the circuit diagram is a bit chocolate fireguard as it's for a US spec car and they seem to have a door lock switch for each door rather than one master for both doors at once.

 

So, it's multimeter time for you :) I'd start at the lock-all switch. If you can suss out which pin does what, you should be able to compare the "unlock" circuit with the "lock" one, and I bet you get either no power fed or no ground switched in when you try and lock it. Follow that circuit to power or ground and you'll find a break in it somewhere.

 

If both doors exhibit the same behaviour I'd say it's not the motors.

 

-Ian

 

Thats a good point, Not the motors because both doors do it.

 

I was going to trace every wire from the central locking switch in the drivers door to where they all end. Do you think that I would more than likely find a break there?

 

Or could it possibly be the Relay for the motors that has blown up. If it is that... do you know where it is ?

 

C..

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Originally posted by TRD3000GT

Thats a good point, Not the motors because both doors do it.

 

I was going to trace every wire from the central locking switch in the drivers door to where they all end. Do you think that I would more than likely find a break there?

 

Or could it possibly be the Relay for the motors that has blown up. If it is that... do you know where it is ?

 

C..

 

Well, according to the circuit diagram, there is a lock/unlock switch for the door key, which says to me that the key works the motor rather than it being mechanical. If it's mechanical, it narrows things down one way, if the key lock works the motor, it narrows things down in a different direction. Can you recall if it's mechanical or not?

 

-Ian

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I have had the door panel off and there is a solid wire that locks and unlocks the doors.

 

its like a bicycle brake, wire sheathed in plastic retainer.

 

Not exactly sure what you mean by the key though.

 

When I unlock the door via the remote both the manual door lock switches flip. But they wont go the other way

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What I mean is, right, is there are four mechanisms for locking/unlocking the door:

 

1. Key

2. Flippy thing

3. Lock/unlock all button

4. Remote plipper

 

Now, 3 and 4 have gotta be an electronic switch that works the lock motors. 2, I think, however, is mechanical - your act of flipping it provides the power to physically lock/unlock the door, the motor is not used at all and it means you can lock/unlock from the inside with no power on. Question is, does 1 use the physical turning action or does it merely close a contact and the motor does the work? According to the circuit diagrams it's a switch, but I would have thought it would be mechanical so you can use the key if the battery is flat...

 

The behaviour of the key points towards your next steps in diagnosis, it's not just a thought exercise :)

 

-Ian

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Right, it won't be anything to do with the alarm. Full stop.

 

According to my Autodata book, there is a Central Locking Control unit, located above the glovebox near side of the car.

I've never seen one, but I have known a similar fault on another Supra and Mark simply rewired it for the customer.

 

The Autodata book is a 1997 book, so it certainly won't cover VVTi's, how different this will be, I don't know...

 

HTH

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Originally posted by Matt Harwood

Right, it won't be anything to do with the alarm. Full stop.

 

According to my Autodata book, there is a Central Locking Control unit, located above the glovebox near side of the car.

I've never seen one, but I have known a similar fault on another Supra and Mark simply rewired it for the customer.

 

The Autodata book is a 1997 book, so it certainly won't cover VVTi's, how different this will be, I don't know...

 

HTH

 

Ok, I guess its in the same place.

 

If I was to look, How would I get in to the Central Locking Control Unit.

 

Remember my car has airbags both sides! So Im not 100% how to get around the problem and yank the unit out!

 

Im SO sure its a dodgy wire in the unit!!

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Bear in mind that I haven't actually seen one. I'd guess that if you start by removing the lower glovebox and side trim, then operate the locking to see if you can hear tiny clicks from nearby relays. (not the easiest thing to hear when the locking motors are operating).

I doubt you'd need to remove the airbags to get to it.

 

If/when you do find it, most relay units can be either unclipped or unscrewed. - My guess is dirty/pitted internal contacts on a relay.

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Only just spotted this thread.

 

And there I was thinking "I bet it's the central locking ECU on the passenger side behind the dash."

 

I have seen one of these and I think I might even have 2 of them lying around in my garage. I'll take a pic later tonight and hopefully get it posted for you to see. I may even have one still in situ on the back of a removed dashboard I have in the shed.

 

From memory, it is almost up against the left side wall above the passenger footwell, alongside the glovebox. But it is attached to the back of the dashboard material, the big bit that goes the width of the car that the glovebox sits in. The Power steering ecu is in the same area I think.

 

:)

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Originally posted by Soop Dogg

Only just spotted this thread.

 

And there I was thinking "I bet it's the central locking ECU on the passenger side behind the dash."

 

I have seen one of these and I think I might even have 2 of them lying around in my garage. I'll take a pic later tonight and hopefully get it posted for you to see. I may even have one still in situ on the back of a removed dashboard I have in the shed.

 

From memory, it is almost up against the left side wall above the passenger footwell, alongside the glovebox. But it is attached to the back of the dashboard material, the big bit that goes the width of the car that the glovebox sits in. The Power steering ecu is in the same area I think.

 

:)

 

Damn, sounds like Im gonna need my pick axe and a long light!!

 

If I was to look at the front of the passenger dash how high up is it?

 

Middle of the top glove box?

 

I really do hope that this is where the problem is!!

 

If you have some spare units, and that is actually what is causing the problem how much do you want for one of them?

 

C.

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Right, here we are, Chris.

 

(Excuse all the crap in the shed at the back of my garage!!)

 

This one is from the other side of the glovebox. (If you can imagine that!) The part you want is the blue box with the orange connector. As you can see, it is just by the air vent nearest the passenger door. It's pretty much in line with the top of the lower glovebox.

 

image

 

This is another angle of the same part in situ on the back of the dash:

 

image

 

 

They can also come in various assorted colours.

 

Here's one (removed) in a nice shade of red!

 

image

 

Hope this helps.

 

Brian.

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Brian,

 

Thanks SO much for doing that, I did have a small attempt last night at finding this unit but failed. I will have another look today after work!

 

Looks to me like you have two spares as well?

 

How much do you want for one of them>? if that is actually my problem.

 

P.S. do you know where the motor for the central locking is ? , I take it that this is just the control box but not the thing that actually phisically moves the door locks open and closed

 

Chris.

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