PACCAR MX (2004 Emissions) Fault Code: P104E Exhaust Gas Pressure Before Turbine – Data Valid but Too Low, During Engine Braking
PACCAR MX (2004 Emissions) Fault Code: P104E Exhaust Gas Pressure Before Turbine – Data Valid but Too Low, During Engine Braking
SET CONDITIONS:
The PCI ECU (D420) detects that the expected exhaust gas pressure before turbine cannot be reached while the VTG turbocharger is at its minimum position.
DIAGNOSTIC CONDITION:
This diagnostic runs when the engine mode is engine brake.
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. The end-stops of the VTG turbocharger actuator not programmed correctly.
IMPORTANT: In an attempt the solve VTG turbocharger actuator position related DTCs, turbocharger actuators are occasionally recalibrated by a technician. By doing so, the actuator is mistakenly calibrated to a smaller span than the initial maximum span of the turbocharger mechanism. In that case, the requested pressure before turbine cannot be reached during engine braking, resulting in DTC P104E.
2. Leaking exhaust system
3. Leaking pressure sensor before turbine tube
4. Pressure sensor before turbine deviation
ADDITIONAL INFORMATION:
1. The VTG turbocharger is used to create back pressure during engine braking.
2. The VTG turbocharger control depends, among other factors, on the exhaust gas pressure before turbine.
3. The VTG turbocharger is controlled by the VTG turbocharger actuator (L037).
4. The exhaust gas pressure before turbine is measured by the pressure sensor before turbine (F826).
