2007 Versa CVT will suddenly lose speedometer function (shows zero mph) and RPM's have to increase to maintain speed. This happens every mile or two. Oddly, I can immediately restart the car and everything runs fine until it repeats,...again. Restarting it ALWAYS resets the problem. I replaced the obvious, the fuel pump and speed sensor. While these things needed to be replaced, and made it run far better, there was no change in the initial problem. Any ideas on what it may be, or has anyone else run into the problem?

The ECM is going into limp mode, probably from a spotty output shaft sensor on your transmission. That's where the speedo signal originates. If you scan it, you'll probably find it's throwing P0720 codes when it misbehaves.

If this is the same as the Speed Sensor, I just replaced it. If it's a different part, where is it located?

There are two sensors on the outside of the trans, did you replace the right one? The output speed is on the back side of the trans and should have Sky Blue, Gray and Black wires. Input speed is on the front and has Orange, Violet, Lt Green. If you did change the right one, get it scanned for codes. The ABS can also cause that behavior if the wheel sensor speeds are disagreeing with the TCM speed.

To be clear, I greatly appreciate your help, but I cannot find any mention of two speed sensors in any online searches. They all keep referring to the speed sensor at the top rear of the CVT. It's dark now, so I'll have to wait till tomorrow to search for anything related to the color wires you've named. Thanks for your help. Can you find a diagram or video? I can't find anything.

The one in front is the input shaft (turbine) sensor, it's basically sensing torque converter output speed. I did some research and it appears that on an '07 CVT, either sensor can make the speedo quit. So you really need to see what codes it's throwing. The rear (output) sensor will generally produce a P0715, the front a P0717, but there are a variety of other codes that might show up. If the front sensor turns out to be the issue I can get you a diagram, but if memory serves, I believe it's buried behind the starter.

Been out of town. It's throwing a P1778 code, input/turbine shaft speed sensor "A" out of range high.

llc3guys wrote: ↑

Sun Aug 08, 2021 5:17 pm

Been out of town. It's throwing a P1778 code, input/turbine shaft speed sensor "A" out of range high.

That's the one on the front.