PACCAR MX (2004 Emissions) Fault Code: U1852 VTG Turbocharger Actuator Software Verification – Incorrect

PACCAR MX (2004 Emissions) Fault Code: U1852 VTG Turbocharger Actuator Software Verification – Incorrect

SET CONDITIONS:
The PCI ECU detects that no or an incorrect calibration verification number (CVN) is received from the VTG turbocharger actuator.

DIAGNOSTIC CONDITION:
This diagnostic runs once when the ignition is keyed on.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition is keyed off for at least 15 seconds and keyed on again, and 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? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. No or intermittent power supply to the VTG turbocharger actuator
2. No or intermittent CAN communication with the VTG turbocharger actuator
3. Incorrect type of VTG turbocharger or actuator installed, only if DTC is active after a VTG turbocharger or actuator replacement
4. Faulty VTG turbocharger actuator

ADDITIONAL INFORMATION:
When the ignition is keyed on, the PCI ECU (D420) queries the VTG turbocharger actuator for a calibration verification number (CVN).

CVN is the calibration verification
number and is the result of a check performed on the software values stored in emission-related ECUs (OBD legislation).