2013 Land Cruiser Fail Safe Mode

[njbrain]

I have a 2013 Land Cruiser with a 5.7 v8 and an AB60f automatic transmission. Randomly and occasionally it will hit failsafe mode while accelerating in 1st gear. Throttle is reduced to approximately 50%, and transmission will not shift into 5th or 6th gear. No codes are stored. There is no specific pattern or reason that I can find for this occurrence and I cannot duplicate on demand. It seems completely random. I thought it was engine ECU so I replaced it. No change. The problem started after installing 4.88 gears, so I bought an HP Tuner and changed the axle ratio to 4.88. No change. The only way to get it out of failsafe is slow down till the transmission shifts back into 1st with 0% throttle application. I have tried cycling the ignition while coasting down the highway, but it is still in failsafe mode upon engine restart. Has anyone run into this, and do you have any ideas for solutions?

[SlowNStock]

I have a 2013 Land Cruiser with a 5.7 v8 and an AB60f automatic transmission. Randomly and occasionally it will hit failsafe mode while accelerating in 1st gear. Throttle is reduced to approximately 50%, and transmission will not shift into 5th or 6th gear. No codes are stored. There is no specific pattern or reason that I can find for this occurrence and I cannot duplicate on demand. It seems completely random. I thought it was engine ECU so I replaced it. No change. The problem started after installing 4.88 gears, so I bought an HP Tuner and changed the axle ratio to 4.88. No change. The only way to get it out of failsafe is slow down till the transmission shifts back into 1st with 0% throttle application. I have tried cycling the ignition while coasting down the highway, but it is still in failsafe mode upon engine restart. Has anyone run into this, and do you have any ideas for solutions?

You mention no stored codes - are you getting any lights on or other issues when it occurs?

[njbrain]

No warning lights of any sort, not even for a second.