KZJ78 Auto issue in low range.

[Gardengnome]

Hi all,

I've done alot of searching and learnt alot about how the A340 transmission shifts but still at a loss to explain whats happening in mine.

In high range everything works great no issues.
Shift into low range and "D" and its only using 2 gears.
Shift down to "2" with no change, already in 2nd?
Shift to "L" and it changes down as expected.
But shift back to "2" and no change, stays in 1st.
Shift to "D" and it shifts up.
Overdrive button makes no effect and overdrive light is not flashing.
Fluid is also nice and red.

Does shifting to low range change the shift patterns? Nothing I have found suggests it does.

Any advice information would be much appreciated.
Cheers, Phil.

[Jerry]

you need to be doing a decent amount of revs to change from 1st low to 2nd low, what does the power button do to things?

[Smurf]

Does it behave correctly in 2 Hi? Once you push the 4wd button on the dash?
If not I would guess it is a computer issue, not sure if yours has a separate 4wd computer though?
As Jerry said they do need higher revs to change up once in low box, but down changes are pretty standard as far as revs go, well in my LJ it is.

[wjw]

Does it behave correctly in 2 Hi? Once you push the 4wd button on the dash?
If not I would guess it is a computer issue, not sure if yours has a separate 4wd computer though?
As Jerry said they do need higher revs to change up once in low box, but down changes are pretty standard as far as revs go, well in my LJ it is.

From memory the 4wd Computer is either behind the kick panel in the passenger foot well or above the glovebox attached to the engine ECU...

[churchill]

On Suzuki's, low ratio locks out over drive limiting the gear box to 3 gears. Not sure if Toyota do the same.

[oldblue]

When I brought my Prado I had the same things with the auto, soon found that this is how the auto behaves. There a many things that controll the shift patterns, ie, speedo pulses, driveshaft RPM, engine RPM, how much touque the motor is developing ( low range very little ) Someone may be able to explane it better.

[Gardengnome]

Cheers to all for the replys.

Good point Keith I'll try it in 4H. I had overlooked that.

Tried it out again last night and agree with Jerry and Keith that the revs need to climb before it will change up. and figure they feel harsher due to the lower gearing.

Again I was only getting 2 gears to operate until I slowed right down to almost nothing (in "L") to do a u turn and then it selected 1st. This almost put me thru the windscreen and the little one in the back hard against her seat straps. Far king low gearing.

During the previous test I never took off in "L", I always started in drive. So I'm thinking that during that run when I put it in "L" the trans wouldn't change down due to the road speed being too high to select 1st. Therefore it staryed in 2nd hence when I changed to "2" it was already in 2nd and when selecting "D" I got 3rd.

So I stopped and took off with it held in "L". 4000rpm in "L' equated to about 10km/h. Speedo hardly moved.

Churchill, I think you right and the ECU negates this option in lowrange to safe gaurd things

Conclusion: The same as Oldblue, the trans is operating fine its the nut twidling the stick and wheel.

This is my first auto 4x4 and I need to get out more and use it.

Thanks to all again. Much appreciated.
See you on the tracks some time. Phil.

[Gyxx]

Hey dude.

I've got a KZJ71 auto. I don't know much about the workings of the control system for the auto box on these but they seem pretty well set up for off-road work. In fact I've gone from being a bit anti auto boxes to preferring them for off-road driving (though I'll still insist that until there's some major technological breakthrough that there is no such thing as a sports car with an automatic transmission).

I've found in low range with the selector in drive the box holds onto first gear very stubbornly and only changes up once the engine speed is quite high - but by backing off the gas once the revs are rising and the engines pulling and then easing back on the gas it'll drop into second very nicely. I've found by using this technique I can control when the shift to second happens very exactly and I get a much smoother shift it's now my usual driving technique when in low range.

I've found in low range first the KZJ walks down steep inclines with great confidence - much better than I would have expected.

I think the brains trust at Toyota turned up for work on the day they were figuring out the box for these vehicles - they've made a convert out of me.

If anyone else reading this post has any insight into the transmission on these please share.

Enjoy the wagon - they're good ones.

[prado_boon]

Agree, low range is exactly that in these boxes and yes the change from 1st to 2nd can sometime be a bit harsh, but it's not that bad! I hardly use low range but when you do it's a good experience especially going down steep inclines.

[kbushnz]

When my prado was factory I used to try and get out of first and get it into second straight away....
Used to leave it in D most he time and only throw it into 1st for descents... If you select it with too much ground speed it will throw your forward in your seat...
Now that I can select what gear I like... typically I start off in 2nd...and forget about first except for descents... And the occasional steep hill starts.
You soon get used to after a full day of cruising around...

[Jerry]

Phil just leave it in high range when you and johnno are on a drive by snowball mission

[Smurf]

I try to avoid letting mine downshift into first if possible as it does grab hard as you say Phil. From standstill a good boot on the gas gets it into second pretty quick for offroad, once moving it doesn't get back into first unless I almost stop.

[tallsam66]

Over drive isn't supposed to work in low range.

[Gardengnome]

Cheers guys all the replies are reassuring that it is all behaving as it should.

I have always been a manual person but after a drive up to lake taylor a couple of weeks back I loved driving the auto. the missus really likes it too which helps as its her daily driver.

Your right Jerry, best to use high range for those in and out snowball attacks