Turbocharger Speed Sensor Circuit Performance

[BobTaylor]

I was coming home from a camping trip this PM when my RAM threw code P2579. I looked it up and saw the explanation in the title. I was pulling my 5er at the time. I've had the turbo cleaning and all the updates done after having P2262s. I'll call the dealer Monday, but I wondered if anyone had any idea what this code was all about.

 

[HBarlow]

What was the situation when it set the code? Were you pulling hard under load at full throttle with the tach near the redline? A situation like that could mean the turbo was actually spinning at an extremely high rpm. If not, it was probably a sensor read error.

 

[BobTaylor]

What was the situation when it set the code? Were you pulling hard under load at full throttle with the tach near the redline? A situation like that could mean the turbo was actually spinning at an extremely high rpm. If not, it was probably a sensor read error.

Just driving along I-40 at 65 mph in flat west Tennessee.

 

[sag2]

I have seen this code after the clean was performed so it may be bad connection or the speed sensor was nicked or damaged during the drill and clean. Don't recall ever seeing it if the sensor was not previously removed, so most likely has to be in the (mis)handling of the sensor.

 

[BobTaylor]

It's been a couple of months or more since the cleaning. What function does this sensor perform?

 

[sag2]

It monitors the actual turbo RPM. The ECM can use it as a reference to see if the turbo is operating, and also to keep it from over speeding. So the ECM changes the position of the nozzle and then looks to see if the speed increases as it thinks it should. Likewise if it senses it is going to get near the safe RPM it can back off the nozzle to keep it from occurring.

 

[BobTaylor]

I got the truck back today and they replaced the Turbo Speed Sensor.