auto wont kick down...

[dmck Junior Member Find all posts View Profile Close dmck]

My prado has been in the family for 7 years now but i have noticed in the last 6 months the transmission isnt as responsive.

It started off intermittently (1 in 5 times) not kicking down after driving for 5-10min. then got more common (every second time), until it just wouldnt kick down at all from 1 min after start up.

Ive had it serviced last week and a full transmission flush yesterday and it is alot better but still wont kick down into first gear like it used to.

My first question would be to see if other peoples prados kick down into first gear (say foot to the floor at 50km/h), or am i asking too much.

Second is what is causing this and how do i fix it?

Its a 2000 petrol/lpg 3.4 GXL 250,000km

[dmck Junior Member Find all posts View Profile Close dmck]

Re: auto wont kick down...

just noticed there are a few topics like this... anyone know where i can get a error check in melbourne and cost? im in richmond

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Re: auto wont kick down...

yeah dmck, if the air flow sensor is dirty/damaged, this is a secondary problem caused by it, the first one being the motor uses more fuel and you loose some power, the second problem it can cause is the communication between the sensor/motor/gearbox is jumbled, so the box wont kick down all the time, (there are two types of air flow sensors, one for the manual the other for the auto, never get them mixed up). If this is what your getting, try cleaning the hot wire in the AFM with a special cleaner.
The other thing that can be the cause, is the kickdown cable may need adjustment.
Also note, that if your trying to get the box to kick down into 1st at 50kph, this will put the motor close to red line, so there will be no actual surge in acceleration.

[dmck Junior Member Find all posts View Profile Close dmck]

Re: auto wont kick down...

i dont really try to kick it down to first in 50 but remember that it used to do something like that if u forced it to..

just the fact taht it wont do it now something must be up.. ill have a look into the airflow sensor ive seen a few posts on it before so ill do a quick search

thanks heaps

[dmck Junior Member Find all posts View Profile Close dmck]

Re: auto wont kick down...

gave the mass air flow sensor a clean today...

like others used crc MAF cleaner...

the little pin was black when i pulled it out and now is nice and shiny again..

gears kick down again into first when i put the foot down but yet to check on the freeway...

thanks for all the help

problem solved until later notice.

Nice not to have the B.O.A.T on my back this time... (Bring Out Another Thousand)

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Re: auto wont kick down...

gave the mass air flow sensor a clean today...

like others used crc MAF cleaner...

the little pin was black when i pulled it out and now is nice and shiny again..

gears kick down again into first when i put the foot down but yet to check on the freeway...

thanks for all the help

problem solved until later notice.

Nice not to have the B.O.A.T on my back this time... (Bring Out Another Thousand)

I thought that would be your problem, the air flow sensor is linked in with the auto box's electronics.

[dmck Junior Member Find all posts View Profile Close dmck]

Re: auto wont kick down...

cheers mate... this is the reason why these forums are so great coz of people like you.. thanks again

[danprado90 Lurker Find all posts View Profile Close danprado90]

Thank you for this thread. I have been trying to diagnose similar problems.

I have a 99 Prado Grande. The gearbox wont kick down from 4th to 3rd when its under load. Its been happening on and off for a few months.

I tried oil changes, did a full gearbox flush, still does it. If I had a full car or towing a trailer it would appear, but just myself in it and nothing it seemed to work fine.

I was gearing up for a full reco gearbox but then I caught this thread.

I checked the kick down cable, tightened it a little but it seemed fine within spec of only 1mm movement.

I decided to undo the air flow sensor to take a look and just on a whim checked the air filter.

A RAT HAD MADE ITS HOME IN THERE! There was a dead rat that had climbed in through the air intake and had jammed itself in between the filter and housing.

I went and bought the Air flow sensor cleaning fluid recommended here for under $30 from super cheap auto and a new filter. Swapped the filter in the carpark and the MAS was cleaned at home in about 20 mins, mostly waiting for the fluid to dry off.

I have been testing it towing a trailer and few other heavy runs and its all been fine. Fixed for under $100 total.

Hopefully this helps anybody having auto transmission/gearbox issues such as random downshift or kick down issues with a 90 or 95 series prado. Check the air intake/airflow sensor.

Thanks for the posters, I wanted to post and hopefully help others