Code No. P1298: Variable Geometry Turbocharger Control System Malfunction (high pressure)


FUNCTION



  • The engine-ECU controls the duty ratio of the variable geometry control solenoid valve so that the actual boost pressure can become the target boost pressure.

TROUBLE JUDGMENT


Check Condition
  • Engine is running
Judgment Criterion
  • Actual boost pressure is higher than target boost pressure by more than 6.7 kPa

FAIL-SAFE AND BACKUP FUNCTION



  • The throttle valve is opened (Electrical discontinuity).
  • The EGR control is stopped (fully closed).
  • The DPF regeneration is prohibited.
  • The fuel injection amount is restricted (Output restriction).
  • The open angle of the accelerator pedal is restricted.
  • The turbocharger control is prohibited.
  • The AS&G control is prohibited.

PROBABLE CAUSES



  • Failed variable geometry turbocharger control system
  • Failed engine-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Check the turbocharger supercharging pressure.

  • Check the turbocharger supercharging pressure (Refer to GROUP 15 - On-vehicle Service - Turbocharger Supercharging Pressure Check ).

Q. Is the check result normal?
Go to Step 2.
Repair the variable geometry turbocharger control system.

STEP 2. M.U.T.-III diagnosis code.

  • After clearing the diagnosis code through M.U.T.-III, start the engine and confirm whether the diagnosis code is set.

Q. Is the diagnosis code set?
Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).