Very slow on steep hills won’t kick down

Hi all, question for the group, I know the 1kzte auto can be a bit sluggish up hills but I am trying to work out if I have something else going on. I have 225/75/16 tyres fitted on my van and I don’t know if this is causing the problem or it is the TPS or something else but whenever my van sees a hill it’s slows down to a crawl. The steeper the hill the worse it is. It seems like the trans won’t kickdown lower than second, even pushing my foot through the floor. I have tried all different driving styles but still bad. I have never driven the van with the 215/70/15 that it came with so I can’t judge. Has anyone else had a problem with the trans not kicking down as it should ? Any advice or experience of similar ? Thanks again

Your van has an A340F which uses Toyota’s version of a TV cable attached to the throttle linkage to determine how much throttle you are giving it. If it’s not adjusted correctly, the transmission has no idea what line pressure to set. If it’s too slack it causes all kinds of downshifting issues.

Videos will show you how to adjust it but it’s easy in practice. Move throttle to Max and then adjust the cable to fit.  Then Crank it up and shift from park to reverse to drive. If it bangs into gear back it off a tiny bit until it doesn’t jerk.

Until it is confirmed adjusted we can only guess as to what’s the problem…however this has a pretty good chance of success. Ours was misadjusted from Japan and shifted like crap. It’s happy now.

Further troubleshooting involves TPS’s, internal transmission solenoids, vehicle speed sensors and the TCM if the above doesn’t address your downshifting issues.

I hope it’s something small and wish you a happy weekend ahead.

I’m assuming you guys are using the acronym of TPS to mean Throttle Position Sensor but this engine doesn’t really have one. It all relies on that throttle cable for line pressure and kickdown as described plus the shifting is controlled via the ECU rather than a TCM.

The first thing I’d be checking for those symptoms is the inline filter for, coincidentally, the TPS - which on this engine stands for Turbo Pressure Sensor. The filter, which looks like a small cotton reel, is in the vacuum line that plugs into the inlet manifold and goes to the TPS. It’s right in front of you when looking at the engine.

And no, it shouldn’t be sluggish up hills. Mine would tow a 1ton trailer up an 8% grade highway easily at 80kph. That turbo pressure sensor filter is a very common problem. It clogs up with oily goop that cycles from the egr into the inlet manifold and stops the ecu from knowing the turbo is spooling & thus adding fuel.