I have a 2014 sr5 hilux 5sp automatic with a 3in exhaust, no chip & no snorkel. Cars done 90,000ks. Just got back from a trip from Perth to Exmouth WA and was having dramas changing into 5th gear.
Basically I’d be driving in 5th going 110kph, overtake or go up a hill, drop into 4th, and when settling back to 110 the car wouldn’t go back into 5th gear. it held 4th gear at 3000rpm and the only way I could get it to change into 5th again was to pull over and turn the car on/off again and off I went until I needed to overtake again.
Seemed to happen only once driving for 4+ hours at a time
i have fitted a trans cooler and the have had the trans serviced and taken to Toyota and they have confirmed I have the latest transmission software.
Any ideas ?? Problem was there before and after cooler/servicing etc