D40 engine code p0720 speed sensor fault

[d-lec]

Thought I would share this one, as I couldn't find it mentioned anywhere else
20yr old daughter borrowed the Nav for a camping trip, goaded into following a couple of Troopies along some serious trails managed to bounce the Nav up and over a rock that smashed the auto transmission pan pretty good. Check Engine light came on later, no effect to operation though. Actually reset itself at home. Next day, check engine light back on and Transmission stuck in first gear. Tilt tray to workshop. Found the trans pan dent and oil out the breather. engine check code P0720 Speed Sensor Fault. Was assuming the worst - new transmission required. Once pan dropped, found wiring for the speed sensor runs through the bottom of the oil pan and had been affected by the dent - the connector had come loose from the wiring being pulled tight from the dent and was giving the engine fault check code. Re-attach connector and a new pan, all good now. Phew. Bash plate time!

 

[Old.Tony]

That's not good at all, and worse still is the error code's name - the code is not listed in the manual, and the D40 specifically does NOT get its speed sensing from the gearbox, it uses the ABS sensors. There is a gearbox output revolution sensor (which used to be used as the speed sensor and still is in some cars, just not the D40) and it's used to make decisions about what gear to put the gearbox in.

Glad to hear it's been resolved, and I guess your daughter has learned something about 4WDing too!

 

[d-lec]

Thanks Tony, yes it was the gearbox output speed sensor, not the Speedo speed sensor.

 

[Old.Tony]

Oh I understood that, but because the code wasn't present in the manual, I googled it and got the same name you gave - undoubtedly because of what the sensor is usually used for.

I suppose what should have irks me even more is the fact that your car got that error code, and Nissan didn't include that error code in the manual.

 

[d-lec]

Well my daughter works at a toyota stealership and it was the workshop boys she was 4wding with and where the Nav got tilt-trayed to. They told her the code and I googled it as well to get to the same conclusion. Must admit even the most senior workshop guy wasn't sure why that particular code was thrown up until the trans pan came off and it became clear the wires had pulled off the connector. Hence why I thought I would share that code with the Nav fraternity...