PACCAR MX (2004 Emissions) Fault Code: U1802 VTG Turbocharger Actuator Power Supply – Data Valid but Too High

SET CONDITIONS:
The VTG turbo charger actuator (L037) detects that the actuator power supply is above 17 volts for more than 40 seconds.

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive after the ignition is keyed off 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?
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
1. VTG turbocharger actuator power supply, check:
– Whether more ECUs on the vehicle detect incorrect power supply
– Battery voltage (faulty alternator)
– VTG turbocharger actuator power supply
2. Faulty VTG turbo charger actuator if the DTC remains active after the above is performed/checked

ADDITIONAL INFORMATION:
The power supply of the actuator is continuously monitored.