P0717 Input/Turbine Speed Sensor Circuit No Signal

[canadian deacon]

I had a problem like that with a dodge caravan. I put the van up on jackstands, started it and put it in drive. I read the voltage off the sensor with a voltmeter. Checked for the voltage at the ecm and had it there. Turned out to be a bad ground rather than the sensor.

[CTScott]

Originally Posted by canadian deacon

I had a problem like that with a dodge caravan. I put the van up on jackstands, started it and put it in drive. I read the voltage off the sensor with a voltmeter. Checked for the voltage at the ecm and had it there. Turned out to be a bad ground rather than the sensor.

On the Yaris the Turbine sensor is a hall effect sensor with both ends being connected directly to the ECM, so this particular issue would not be a ground issue on the Yaris, but it could be corrosion of the connector terminals that plug into the sensor.

[canadian deacon]

Originally Posted by CTScott

On the Yaris the Turbine sensor is a hall effect sensor with both ends being connected directly to the ECM, so this particular issue would not be a ground issue on the Yaris, but it could be corrosion of the connector terminals that plug into the sensor.

I misspoke in my explanation. The caravan speed sensor has a similar design as the yaris. I meant to say that I followed the signal back to the transmission control module so I knew the sensor and wiring were okay to that point.

I found a bad ground lead off of the transmission control module. The lead had been back probed and the hole had never been sealed. The wire corroded through in two or three places along its length. Hard to find but cheap to repair.