Insite says turbo spinning when truck isn't running

[Rawze]

Some ecm programs will estimate the rpm of the turbo if the sensor fails. - Until it sees a good sensor, it will not jump back to using the actual sensor, and have a low-default value that it reads all the time. something like 8k-rpm or something if memory serves me right.


Put in the new speed sensor and run it for about 20 minutes or so and go from there.
Like snailexpress says, could also be the wiring in the harness somewhere.

I have helped a couple others who had that same issue, no one could find it, and ended up turning off the option for turbo speed estimation using C0alterm. it is actually an option that can be turned off so that you only get and see what the actual sensor is reading.