4WD automatically engaging

[Millhouse Lurker Find all posts View Profile Close Millhouse]

Good People,
The other day I experienced my 2007 GXL Auto automatically engaging 4WD - This is the 2nd time that this has happened!
I was driving into a multi-storey car-park at the time - and got myself into a nasty Diff Wind up that I could not get out of.

The first time this happened I put this down to the passenger bumping the 4WD lever. This time I was the only person in the car and no where near the 4WD selector lever.

Toyota don't believe this can happen automatically - and suggest must have been bumped!

(Note that I have a Diff problemn at the moment that Toyota are investigating but tell me is unrelated - I'm experiencing a shudder/grabbing sensation in rear of vehicle at low speeds and when turning - feels a bit like Diff wind-up - on a small scale)

Anybody heard of something like this before?

Thanks

[Way2go Member Find all posts View Profile Close Way2go]

Re: 4WD automatically engaging

Not sure how the vehicle can be "automatically engaging 4WD" - it's always in 4WD (i.e. it's a full-time 4WD).

Are you meaning that the centre diff is engaging by itself? That would lead to wind-up. I assume the GXL has a centre diff button (my Grande does), and a light on the dash when it is engaged - is this what you are getting? The button isn't exactly in a place where it would get knocked by accident.

Pasenger bumping the 4WD lever would only change the gearing from 4WD high (where it is dya-to-day) to either neutral or 4WD low-range.

[pjorek Advanced Member Find all posts View Profile Close pjorek]

Re: 4WD automatically engaging

GXL don't have the button. He means locking the centre diff automatically.

[Schaffer Addicted PP Member Find all posts View Profile Close Schaffer]

Re: 4WD automatically engaging

I assume the GXL has a centre diff button (my Grande does), and a light on the dash when it is engaged - is this what you are getting? The button isn't exactly in a place where it would get knocked by accident.

As per what pjorek indicated, the GXL and GX (and possibly the VX) all have this combined into a a lever. When pulled back this is in high (H) with an open centre diff, pushed forward once this is high (HL) with closed centre diff, then you must put transmission into neutral and then push the transfer level right and then forward through neutral and then into low (LL) with a closed centre diff. I assume on the Grande it is bascially the same except there is no option there for open and closed centre diff on the transfer gear as you manage this through a button.

[Hutch Addicted PP Member Find all posts View Profile Close Hutch]

Re: 4WD automatically engaging

Good People,
The other day I experienced my 2007 GXL Auto automatically engaging 4WD - This is the 2nd time that this has happened!
I was driving into a multi-storey car-park at the time - and got myself into a nasty Diff Wind up that I could not get out of.

The first time this happened I put this down to the passenger bumping the 4WD lever. This time I was the only person in the car and no where near the 4WD selector lever.

Toyota don't believe this can happen automatically - and suggest must have been bumped!

(Note that I have a Diff problemn at the moment that Toyota are investigating but tell me is unrelated - I'm experiencing a shudder/grabbing sensation in rear of vehicle at low speeds and when turning - feels a bit like Diff wind-up - on a small scale)

Anybody heard of something like this before?

Thanks

Does tghe light come as well???

[MDS69 Advanced Member Find all posts View Profile Close MDS69]

Re: 4WD automatically engaging

I assume the GXL has a centre diff button (my Grande does), and a light on the dash when it is engaged - is this what you are getting? The button isn't exactly in a place where it would get knocked by accident.

As per what pjorek indicated, the GXL and GX (and possibly the VX) all have this combined into a a lever. When pulled back this is in high (H) with an open centre diff, pushed forward once this is high (HL) with closed centre diff, then you must put transmission into neutral and then push the transfer level right and then forward through neutral and then into low (LL) with a closed centre diff. I assume on the Grande it is bascially the same except there is no option there for open and closed centre diff on the transfer gear as you manage this through a button.

If you have option pack 1 on the GXL then you only have H or L on the stubby stick and a button on the console forward of the gear stick or shifter (like the Grande). We have accidently locked the centre diff by putting stuff on the console like wallets etc and "bumped" the button locking the centre diff.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Re: 4WD automatically engaging

On the basis that the car in question uses the stubby lever to select 4wd... Here is a similar story...

Two Prados ago I had a diesel P....o. It did exactly the same thing a couple of times. The first time the wife reported the phenomenon I dismissed it as something/someone bumped the lever. The second time it did it I was driving and I actually saw the lever move! On its own!! Took it to the dealer who said much the same things as I did the first time. Without the swearing obviously.

After a few weeks of random 4wd engagement I worked it out. I had staked a tyre a few weeks before and as the tyres were only about half worn I replaced two tyres only. Ran these on the front with worn tyres on the back (the third worn tyre went on the spare). The difference in diameter was what caused the 4wd system to engage. Confused the guts out of the constant 4wd system. I changed the rear tyres and the problem went away. True story.

So have you changed one or two tyres recently and the others are worn?

As for the button engagement I too have had the centre diff lock driving along the road. Passenger was changing the charging cables over from ipod and the button was bumped. Mild panic ensued.

[Bazza Senior Member Find all posts View Profile Close Bazza]

Re: 4WD automatically engaging

The low range engaging is an interesting one! The rear end issue issue is similar to what I've been experencing on my 09 120 V6 GLX. Mine does somthing similar from a fast start. If you take off slowly, all is good. I'll be interested to see how your issue is resolved. I'll be taking it up with Toyota on the next service.

Bazza.

[ozwapet2 Advanced Member Find all posts View Profile Close ozwapet2]

Re: 4WD automatically engaging

Seems like Mr. Millhouse needs to come back with more info.

If his GXL has Option Pack 1 like mine, as said above he will have a switch to engage CDL. It probably is good to determine if this switch exists on his.
Having said that I don't think OP 1 was available on 2006 models.

[Millhouse Lurker Find all posts View Profile Close Millhouse]

Re: 4WD automatically engaging

Thanks to all those who have participated thus far.

First some clarifications:
I should have described he problem as Central Diff Lock engaging as this is what happened - Thanks Way2go ;-)
My Prado does not have a pushbutton Central diff lock - This is managed mechanically via the High/Low range selector lever.
At the time it happend the central diff lock lamp illuminated on the dash.

The rear diff had been progressively getting worse since the last service - I took it in to Toyota for investigation - they thought that the wrong grade of Diff oil had been used - they flushed and drained and replaced diff oil & said to give it 2 weeks.
1 Week later - no significant improvement noticed then the central diff locked up as described.

This time Toyota replaced clutch plates - suggested that they were sticking due to wrong oil being used. Just picked up the vehicle today - will see how it performs - but still no answer on how centre diff engaged - I think mjrandom ay have a plausible explanantion - however in this case the first thing I checked was the position of the lever and it was in correct posisiton???

Thanks

[StormyKnight Advanced Member Find all posts View Profile Close StormyKnight]

Re: 4WD automatically engaging

The lever itself only controls the high/low transfer gear mechanically with the centre diff lock being done electrically....

Sounds like the switch or wiring on the transfer lever may be at fault....

The transfer lever switches the locking mechanism for the CDL to lock. When the CDL locks the light comes on. Locking of the CDL requires that the two parts line up which mean that sometimes you have to drive a bit turning the wheel to get it to lock.

...How do you unlock it once the lights on?

Cheers

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Re: 4WD automatically engaging

I guess we need clarification of what is happening. Is the lever moving of its own accord and selecting HL or is the light just coming on and the centre diff locking without the lever actually moving? The former needs some outside influence such as the tyre diameter difference as I described as my experience. The latter could be an electrical short or other electrical problem. Each one requires a different troubleshooting method. Please advise.

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: 4WD automatically engaging

If you have a button to lock the centre diff then it's an electrical actuator, if it's via the stubby lever then your diff lock is 100% mechanical with the only electrical part being the switch that activates the light on the dash.

Mick