TL;DR - Has anyone had any luck using an aftermarket step motor to repair a blown CVT with a P1777 code?


Car WAS driving fine. Car WAS getting about 30 MPG. Even passed an OBD2 emissions test in VA a few months ago with no problems.

All of a sudden, the check engine light came on and it would not accelerate.
Scanned codes, Only code is P1777.
Engine would not free-rev in Park or Neutral.

Disconnect the TCM and I CAN get the car to move in low gear range; reverse and 1st essentially. Just enough to get it on a trailer or tow truck.

Followed the procedure here:
http://www.nialtima.com/p1777_step_motor-1037.html

I'm not getting the right resistance at the TCM connector.
30 ohms on 29 and 30...
Only 2 ohms on 27 and 28...

Step Motor is blown.

Nissan doesn't sell it, it's only available with a new valve body.
However it seems to be available aftermarket:
https://smile.amazon.com/gp/product/B07VK3DMP8

Has anyone had any luck replacing one of these or using a scrapyard valve body?


2007 Nissan Altima 2.5 S
93K miles on the clock.

Well under the 120K mile warranty that Nissan has... But unfortunately well over the 10 year mark. Nissan won't honor it.

The QR25DE engine runs great. Kinda crappy when Japan's 3rd largest automaker can't make a drivetrain that lasts longer than 100K miles. Maybe it's Peugeot's grubby little hands in the pot, kinda like how Mazdas made under the Ford era are kinda crappy.

Welcome aboard, Pele!

I think you've nailed it with your assessment We've grumbled about the CVTs since Nissan first started saddling otherwise-good vehicles with them.

Certainly a misguided effort, in hindsight. I'd guess you've got nothing to lose by attempting the repair, but I'll let others chime in who may know better.

Essentially, you have a paperweight otherwise. Bummer, since the 07 Alty is a nice car.