PACCAR MX (2004 Emissions) Fault Code: P1724 Exhaust Gas Pressure Before Turbine – Data Valid but Too High

PACCAR MX (2004 Emissions) Fault Code: P1724 Exhaust Gas Pressure Before Turbine – Data Valid but Too High

SET CONDITIONS:
The PCI ECU (D420) detects that measured pressure before turbine is higher than the requested pressure before turbine for more than 40 seconds.

DIAGNOSTIC CONDITION:
This diagnostic runs continuously when the engine is running at a steady load.

CORRESPONDING OBD READINESS MONITOR:
VTG monitor

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 following conditions:
– Corresponding readiness monitor displays ‘Ready’
– Diagnostic conditions are met
– Set conditions are met
3. Did the DTC come back?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. Restriction in EGR circuit
2. Restriction in exhaust system
3. Pressure sensor before turbine deviation
4. Incorrect calibration of the VTG turbocharger actuator
5. Mechanical defect of the VTG turbocharger actuator (internal bearing wear)

ADDITIONAL INFORMATION:
1. The PCI ECU uses pressure before turbine:
– To make EGR gas flow toward the inlet possible
– To generate boost pressure
– For engine braking
2. The pressure before turbine is measured by the pressure sensor before turbine (F826).