PACCAR MX (2004 Emissions) Fault Code: P2579 Turbo Speed – Abnormal Rate of Change

PACCAR MX (2004 Emissions) Fault Code: P2579 Turbo Speed – Abnormal Rate of Change

SET CONDITIONS:
The PCI ECU (D420) detects that the measured turbo-speed signal is out of range or changing abnormally.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the engine is running.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Exhaust gas leakage between engine and VTG turbocharger
2. Displaced turbo-speed sensor (loosened sensor bolt)
3. Faulty turbo speed sensor wiring
4. Faulty turbo speed sensor

ADDITIONAL INFORMATION:
1. The turbo speed is measured by the turbo speed sensor (F683).
2. Engine torque is reduced.