1993 - Prado - RHD - 1KZTE 3.0L Turbo Diesel I4 - Transmission O/D Issue (1 Viewer)

[LCYOTA]

Hi all,

I'm new here. I just purchased a 1993 Prado and I'm having an issue with the transmission shifting from 3rd to 1st when I come to a stop. It's an automatic. I can shift it into L and 2nd with no issue from the start off, but 50% or more of the time, it won't shift back down into 1st when I come to a stop
I have an O/D off light that flashes at me as well. Please advise if anyone has run across this. It's at the shop right now, but I wanted to see if anyone had some input

 

[KiwiBogan]

Niiiice bus! Looks tidy as! I've never had issues with my auto trans (touch wood) but if I was to hazard a guess, it kind of sounds like a wiring issue or failing solenoid on the transmission itself? The A343F auto trans is controlled by the ECU. Although I've read of a few cases, I'm not entirely convinced failed ECUs are a common problem with the Prados so doubt that would be the source of the problem. And the auto trans are famous for being fairly unbreakable. In saying that, it's a 5 min job to pull the ECU out from behind the glovebox and inspect, so maybe worth doing if the problem isn't obvious.

I'd start simple by inspecting the wiring going to the plugs on the trans for breaks of chaffing, maybe a loose or dirty connection. From memory, at least one of these connectors is in a terrible spot between the top of the trans and the underside of the car. Check the wiring to the overdrive switch on your gear shifter and that the switch is functioning correctly. Also smell the trans fluid. If it smells burnt, it might be time to drop the trans oil and run a new filter kit through it. This is a fairly cheap and straightforward job and will give you a chance to inspect the magnet in the pan for any chunks/grinds of metal giving you some indication of the condition of the transmission internals.

All just guesses here. I've had a bunch of weird issues with my 2000 Prado due to aging wiring becoming brittle from hot engine bay temps and wiring and connectors getting damaged during mechanical work. So I almost always suspect wiring these days whenever something plays up haha.

Good luck with it mate, looks like you scored a really cool car. I hope it serves you well

 

[AirheadNut]

If the OD light is flashing there might be an error code you can read by jumping a couple of pins in the diagnostic port (I can't remember exactly which ones, but there are plenty of threads about it here on Mud). I would hazard a guess that the shift solenoids are going out; luckily they're not expensive and relatively easy to replace. If you haven't changed out the transmission fluid yet it would be good to do that anyway.

 

[LCYOTA]

Thanks, I appreciate everyone chipping in! I will take any thoughts or suggestions, nothing I won't take a shot at!