I was driving my car up a hill in cruise and my car popped out of gear. It would not shift up and rpms would just keep climbing. I tried shifting in manual mode but It would not shift up.

I slowed down and pulled over and it shifted down just fine and came to a stop. There was no weird smells or anything and appears to be no exterior damage. I turned the car off then turned it back on and everything shifted just fine again. I drove it for a couple days with no problems shifting again since.

I took the car to auto zone and this is the code that it threw:

P1730 Automatic Transmission Interlock

Possible causes:
Faulty low coast brake solenoid valve
Low coast brake solenoid valve harness is open or shorted
Low coast brake solenoid valve circuit poor electrical connection
Faulty Automatic Transmission Fluid (ATF) pressure switch 2


I called an infinity dealership and they said they haven't ever heard of that code before. They did however want me to pay $80 to hook it up to a scanner even though I just told them I already did that. (What crooks)

Anyways, can anyone help me out please? I don't know what to do about this, does anyone have a clue what might be going on???

Any help is appreciated, thank's for reading guys.

 

Their "scanner" is much more comprehensive than the OBD2 scanner the parts house used. They will hook it up to Consult-II/III which can run a diagnostic of the transmission to determine the ACTUAL CAUSE.

My guess is you're low on ATF and when the vehicle was pointed uphill it sucked air for a second which caused the drastic loss of hydraulic pressure and caused it to go into safety mode to prevent transmission damage as intended.

Get it up to temp after a nice drive, park and run the vehicle through EACH GEAR, leave the engine running, pull off the 12mm bolt holding down the dipstick and check your fluid 5-6 times wiping down the dipstick each time, you're probably about half low or maybe a tad more.

If you haven't been servicing your transmission with a drain and fill every 30k as required by the manufacturer then just go in to Nissan and get it done, they will fill to the proper level. Don't use ANYTHING other than Nissan Matic-J or S or your tranny won't work.

Nissan is cheaper than Infiniti btw.