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 ).