Not starting, lurches into gear

[RZNT4R]

https://demos.starbase7.net/t3Portal/

Navigate to 2015 Repair Manual > DRIVETRAIN > TX6A AUTOMATIC TRANSMISSION / TRANSAXLE > AUTOMATIC TRANSMISSION SYSTEM

You'll find the complete wiring diagram in > SYSTEM DIAGRAM, pinouts at > TERMINALS OF ECU (sorry, I said test at PCM, I meant test at TCM which is on the other side of the dash, I'm too used to cars that have transmission functions integrated in the PCM), and a complete troubleshooting workflow in the header dedicated to the trouble code you've got. The basic diagram in > P0707,P0708; Transmission Range Sensor "A" Circuit Low shows all the PNP does is take 12V from IG1 #1 relay and Backup Lamps fuse and patches it to one of 4 pins on the TCM depending on the position.

*** this brings up a good point! check your BKUP LT fuse ***

So with your DVOM set to voltage, you can backprobe each of those wires at the TCM to see if the PNP switch is sending voltage to the appropriate circuit in each position.

[Abz 86]

Originally Posted by RZNT4R

https://demos.starbase7.net/t3Portal/

Navigate to 2015 Repair Manual > DRIVETRAIN > TX6A AUTOMATIC TRANSMISSION / TRANSAXLE > AUTOMATIC TRANSMISSION SYSTEM

You'll find the complete wiring diagram in > SYSTEM DIAGRAM, pinouts at > TERMINALS OF ECU (sorry, I said test at PCM, I meant test at TCM which is on the other side of the dash, I'm too used to cars that have transmission functions integrated in the PCM), and a complete troubleshooting workflow in the header dedicated to the trouble code you've got. The basic diagram in > P0707,P0708; Transmission Range Sensor "A" Circuit Low shows all the PNP does is take 12V from IG1 #1 relay and Backup Lamps fuse and patches it to one of 4 pins on the TCM depending on the position.

*** this brings up a good point! check your BKUP LT fuse ***

So with your DVOM set to voltage, you can backprobe each of those wires at the TCM to see if the PNP switch is sending voltage to the appropriate circuit in each position.

A little update, I decided to give the car to a different Toyota dealership and this is what the came up with.(attached JPEG) This is probably the fourth time I've been told it's the park/neutral safety switch. And have since got 2 second hand ones and neither have solved the problem. The rear light issue seems interesting. I am going to revert the reverse light back to stock and replace the fuse and see if anything changes

[RZNT4R]

Originally Posted by Abz 86

(attached JPEG)

JPEG not attached

[Abz 86]

Originally Posted by RZNT4R

JPEG not attached

I discovered the issue yesterday. And my god, I am physically unable to shake my head enough. I swapped my headunits to an android headunit some time ago, but I didn't connect the reverse camera. I just left it as a naked wire inside. After reading a wiring diagram I decided to fully unplug the headunit and replace the bkup light fuse. AND IT WORKED all the dash lights are off, the car turns on functions normally. I cant believe that something so simple was the cause of all these issues and all this trouble

[RZNT4R]

Originally Posted by Abz 86

The cause was human all along

What did I say on the first page?

"I've seen what people do trying to fix cars and let me tell you, it's nasty."

And your last dealership adventure is in line with what I expected: they had a code and tried to throw a part at it. They didn't try to find the issue.

May this be a lesson: any person looking at even the basic diagram would have seen the fuse, and the first thing you check is the fuse. The dealer tech didn't check the fuse. You checked the fuse. You win (even if you caused the issue :P )

[arrow34]

Hey! You saved my sanity. It was blown for me too. I replaced it in my car. Started functioning normally, but it blew again. My backup unit is hooked up and nothing is changed but it blew again. I'm not sure what the problem is but I disconnected my backup and going to get some more fuses and do some testing