4 Speed auto rolling back when in drive

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

Hi I need some help with this.

I have just carried out the "amts" mod to strengthen my shift lever. I fully removed the shift assembly from the car before carrying out there mod. The mod works great and the shifter feels much better. The Prado drives normally but now the auto does not seem to hold the car from rolling on hills back very well. Normally it would hold the car no problems on my drive way, now as soon as you take your foot off the brakes the car rolls back and the hill start assist kicks in.

I have been parking in the same spot on my driveway for several years and never had this happen before, now it happens every time I stop there. I have pulled the shift lever assembly out again and checked over it, nothing obvious that I could see. Have I stuffed something up?

Any help would be greatly appreciated

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

Update - Im still having the problem. I have been driving the car throughout the week and it seems to drive normally, when I select D or R I feel the transmission load up as normal. However even on a gradual incline the car still rolls backwards when in Drive. When I come to a stop on a slope I need to keep my foot on the brake otherwise it rolls backwards reasonable quickly, similar to a manual transmission when you put the clutch in but forgot to brake. Its defiantly a bit disconcerting.

Are there any transmission guys out there? I have done lots of Goggling on the Toyota A343F transmission with little success.

Kevin

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Sure all the wiring looms are plugged back in ?? None left laying about not connected under there ?? If it was working before then must be some thing not hooked up ?? although you have checked it again. What fuse controls that feature ?? Maybe some thing shorted out when playing about ?? Only guessing here....Cheers Steve

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

Hi Steve, I have the shift assembly out several times thinking I must have missed something. There is only one plug going into it and I have checked that it is nice and secure. Your right, if it was working fine before than it must have been something I did, just not sure what. The whole setup if very basic so not much can go wrong, well at least not till I touched it

I just ducked out to the shed and disconnected the battery. If in doubt disconnect the battery I say , might be an ECU issue so this should reset it. Will put it back together in the morning, fingers crossed.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Sorry mate cant think of anything else. I have just done a google search on it and nothing at all mentioned. Cant even find anything on the fuse that controls the hill hold.....Cheers Steve

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

No problems Steve, thanks for your effort.

Disconnecting the battery over night made no difference. I found a section in my repair manual on testing the ECU so I will get the multimeter out over the weekend and make sure it is as it should be.

After seeing tomorrows weather report I have decided to have a sulk and go fishing instead of looking at the Prado, its annoying me at the moment so it can wait.

Kevin

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

Hi Kev,

I have the same car (2003 V6 Grande, 4sp Auto) and mine has done that since the day I bought it.

I load up the converter a little by giving it a touch of accelerator and it will sit on the spot easily.

I know that this is in no way related to the work you did fixing the shifter but is the car idling a little lower and therefore not loading up the box like previously?

Just a thought.

[macaroon1 Advanced Member Find all posts View Profile Close macaroon1]

Just trying to help. I've the 1KZ but same everything else. My driveway is at least @45degrees??. Like Pitbull it does exactly the same, have to give it a little acceleration to load up the converter. Never needed/tried to keep it in the same spot thou!! Always rolls back a little before hill start kicks in. FWIW I try and use the handbrake like a manual transmission i.e same as manual hill starts. Showing my age now as my g.f was recently taught to drive and encouraged to ride the clutch when at slight inclines (lights etc)??? The instructor complained how expensive (manual) clutches were.

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

Thanks for the reply guys, sounds like a common thing. Im starting to second guess myself now, maybe the car has always been like this and I haven't noticed. Maybe because I had been working on the shifter I was paying more attention to it?

The car idles and drives perfectly so maybe this is normal, strange that it has taken 3 years to notice it though.

[Davis Dieso Junior Member Find all posts View Profile Close Davis Dieso]

Sometimes the little pins in those plugs can bend over and not make contact (of course). Looks good on the outside.

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

Try running the stick through each gear, if the gear selector lights work ok
everything is plugged in and working.

As the gear box is electronic it should also be working ok, sure its not just imagine
as you have been playing with the gear box?

Leigh