Code No. P0299: Turbocharger Under Boost Condition




FUNCTION



  • The engine-ECU checks whether the boost pressure is not lower than the specified value.

TROUBLE JUDGMENT


Check Condition
  • Engine is running
Judgment Criterion
  • The opening degree of accelerator pedal is 23% for 3 seconds and the boost pressure is not lower than the specified value.

FAIL-SAFE AND BACKUP FUNCTION



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

PROBABLE CAUSES



  • Intercooler air hose disconnected or damaged
  • Vacuum hose of manifold absolute pressure sensor disconnected or damaged
  • Failed manifold absolute pressure sensor
  • Failed engine-ECU

DIAGNOSIS PROCEDURE


STEP 1. Check on intercooler air hose.



  • Check whether the hose between turbocharger and inlet manifold is disconnected or damaged.

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 Service- Turbocharger Supercharging Pressure Check <4N1> ).

Q. Is the check result normal?

Go to Step 4.
Repair.

STEP 4. Check on clogged intercooler.


note When checking the clogged intercooler, make a visual check or use an air blower.

  • Check whether the intercooler is being clogged or not.

Q. Is the check result normal?

Go to Step 5.
Replace the intercooler.

STEP 5. Check on clogged EGR cooler.


note When checking the clogged EGR cooler, make a visual check or use an air blower.

  • Check whether the EGR cooler is being clogged or not.

Q. Is the check result normal?

Go to Step 6.
Replace the EGR cooler.

STEP 6. Check on clogged EGR pipe (A, B).



  • Check whether the EGR pipe (A, B) is being clogged or not.

Q. Is the check result normal?

Go to Step 7.
Replace the EGR pipe (A, B).

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



  • Reconfirmation of diagnosis code.

Q. Is the check result normal?

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