P2579 code

[RideSlow2004]

Got the code at the end of a 500 mile trip, pulling the trailer. Had run freeway, state routes, and back roads. Was 1/2 mile from home, at 25 mph on level ground. Mechanic at my city scanned it and cleared it. Truck currently has 75,000 miles. (I bought it new for hauling RV's and snow skiing) 2007 6.7 4x4 QC 3500 SRW automatic. EB is always on. Getting ready for a 2500 mile trip in Sept.

Thoughts?

 

[Bob4x4]

heory of Operation

The Turbocharger Speed Sensor is a variable reluctance speed sensor. It consists of a coil of wire and an iron core. The target on the turbocharger shaft is a ground flat surface in the center of the shaft. As the flat surface on the turbocharger shaft spins past the speed sensor, a signal is generated. The Engine Control Module (ECM) interprets this signal and converts it to a turbocharger speed reading. This monitor is a two trip fault. The MIL lamp will turn off once the diagnostic runs and passes in four consecutive drive cycles.

When Monitored:
Engine running, turbo speed estimate is greater than a calibrated threshold.

Set Condition:
The Engine Control Module (ECM) calculates an estimated turbo speed. The fault is activated when the difference of speed between the Turbo Speed Sensor and the turbo speed estimate is greater than a calibrated value. The fault is also activated if the Turbo Speed Sensor reading goes above a calibrated limit.


Possible Causes

(K540) TURBO SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(K540) TURBO SPEED SENSOR SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
(K540) TURBO SPEED SENSOR SIGNAL CIRCUIT SHORTED TO THE (K541) TURBO SPEED SENSOR GROUND CIRCUIT
BOOST PRESSURE SENSOR
TURBOCHARGER SPEED SENSOR
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control

 

[RideSlow2004]

Thank you. Based on what you wrote, I need to have a shop that can follow those procedures take a look at the truck.