Code No. P1299: Variable Geometry Turbocharger Control System Malfunction (low 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 lower than target boost pressure by less than 6.7 kPa

PROBABLE CAUSES



  • Failed variable geometry turbocharger control system
  • Clogged intercooler
  • Clogged EGR cooler
  • Clogged EGR pipes A and B
  • Failed engine-ECU

DIAGNOSIS

STEP 1. Check on intercooler air hose.

  • Check the lines between the turbocharger and the intake manifold for poor connection or damage.

Q. Is the check result normal?
Go to Step 2
Repair.

STEP 2. Check on vacuum hose of manifold absolute pressure sensor.

  • Check whether the vacuum hose of manifold absolute pressure sensor is disconnected or damaged.

Q. Is the check result normal?
Go to Step 3
Repair.

STEP 3. Check turbocharger supercharging pressure.

  • Check turbocharger supercharging pressure (Refer to GROUP 15 - On-vehicle - Turbocharger Supercharging Pressure Check <4M4> ).

Q. Is the check result normal?
Go to Step 4
Repair.

STEP 4. Check the intercooler for clogging.

  • Check the intercooler for clogging by visual inspection or using an air blower.

Q. Is the check result normal?
Go to Step 5 <Euro5>
Go to Step 7 <Except Euro5>
Replace the intercooler.

STEP 5. Check the EGR cooler for clogging.

  • Check the EGR cooler for clogging by visual inspection or using an air blower.

Q. Is the check result normal?
Go to Step 6
Replace the EGR cooler.

STEP 6. Check EGR pipes A and B for clogging.

  • Check the EGR pipes A and B for clogging by visual inspection or using an air blower.

Q. Is the check result normal?
Go to Step 7
Replace the EGR cooler.

STEP 7. M.U.T.-III diagnosis code

  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ). After registering the injector identification code, the vehicle equipped with the closed type DPF carries out the forcible DPF regeneration. (Refer to GROUP 17 - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).