Dtc P0234/34 Turbocharger / Supercharger Overboost Condition


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0234/34, P0299/34 AND /OR P1251/34)

READ VALUE USING INTELLIGENT TESTER (MAP)

CHECK EXHAUST SYSTEM

CHECK AIR CLEANER FILTER

CHECK INTAKE SYSTEM

INSPECT TURBOCHARGER SUB-ASSEMBLY

CHECK ECM (VNTI VOLTAGE)

CHECK ECM (VNTO VOLTAGE)

CHECK EGR VALVE ASSEMBLY

INSPECT INTAKE AIR TEMPERATURE SENSOR

DTC P0234/34 Turbocharger / Supercharger Overboost Condition

DTC P0299/34 Turbocharger / Supercharger Underboost

DTC P1251/34 Step Motor for Turbocharger Control Circuit (Intermittent)


DESCRIPTION

HINT:
*: Only for 1KD-FTV
Refer to DTC P0045/34 (Toyota Fortuner RM000000YGU003X_01.html).

DTC No.
DTC Detection Condition
Trouble Area
P0234/34
When turbocharger boost pressure continues to be higher than ECM's target boost pressure.
(1 trip detection logic)
  1. Turbocharger sub-assembly
  2. Turbo motor driver
  3. Manifold absolute pressure sensor
  4. MAF meter
  5. EGR valve stuck closed
  6. Exhaust system and intake system are modified or clogged
  7. ECM
P0299/34
When turbocharger boost pressure continues to be lower than ECM's target boost pressure.
(1 trip detection logic)
  1. Turbocharger sub-assembly
  2. Turbo motor driver
  3. Manifold absolute pressure sensor
  4. MAF meter
  5. EGR valve stuck open
  6. Manifold absolute pressure sensor (hose disconnected)
  7. Exhaust system and intake system are modified or clogged
  8. ECM
P1251/34
When turbocharger boost pressure is higher than boost pressure for a short time in which there was possibility of engine damage.
(1 trip detection logic)
  1. Turbocharger sub-assembly
  2. Turbo motor driver
  3. Manifold absolute pressure sensor
  4. MAF meter
  5. EGR valve assembly
  6. Exhaust system and intake system are modified or clogged
  7. ECM

WIRING DIAGRAM

Refer to DTC P0045/34 (Toyota Fortuner RM000000YGU003X_03.html).

INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, and other data from the time the malfunction occurred.
NOTICE:
If the ECM is replaced, the new ECM needs initialization (Toyota Fortuner RM0000012X2005X.html).
1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0234/34, P0299/34 AND /OR P1251/34)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

  1. Enter the following menus: Powertrain / Engine / DTC.

  1. Read the DTCs.

    Result:
    Display (DTC Output)
    		Proceed to
    P0234/34, P0299/34 and/or P1251/34
    		A
    P0234/34, P0299/34 and/or P1251/34 and other DTCs
    		B


B
GO TO RELEVANT DTC CHART
A


2.READ VALUE USING INTELLIGENT TESTER (MAP)

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine and warm it up. Turn the intelligent tester ON.

  1. Enter the following menu: Powertrain / Engine / Data List / MAP.

    Standard value (reference):
    Item
    		Engine Speed*
    		Specified condition
    MAP
    		Ignition switch ON
    		Same as atmospheric pressure
    Idling
    		95 to 105 kPa
    (713 to 788 mmHg, 28.1 to 31 in.Hg)
    3,000 rpm (no engine load)
    		110 to 135 kPa
    (825 to 1,012 mm Hg, 32.5 to 39.9 in.Hg)
    HINT:
    *: If no idling conditions are specified, the A/C switch and all accessory switches should be OFF with a fully warm engine.


NG
REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR
OK


3.CHECK EXHAUST SYSTEM

  1. Turn the ignition switch ON.

  1. Check the exhaust pipe for leaks.

    OK:
    Exhaust pipe has no leaks.


NG
REPAIR OR REPLACE EXHAUST SYSTEM
OK


4.CHECK AIR CLEANER FILTER

  1. Check that the air cleaner filter is not clogged.

    OK:
    Air cleaner filter is not clogged.


NG
REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY
OK


5.CHECK INTAKE SYSTEM

  1. Disconnect the air cleaner hose.

  1. Use a mirror to visually check the turbocharger for any mechanical problems.

  1. When the engine is cold, check that the impeller of the turbocharger rotates smoothly, and perform a contact check to confirm whether there is any damage on it.

    OK:
    impeller of turbocharger rotates smoothly.


NG
REPAIR OR REPLACE INTAKE SYSTEM
OK


6.INSPECT TURBOCHARGER SUB-ASSEMBLY

  1. Disconnect the air cleaner hose.

  1. Use a mirror to visually check the turbocharger for any mechanical problems.

  1. When the engine is cold, check that the impeller of the turbocharger rotates smoothly, and perform a contact check to confirm whether there is any damage on it.

    OK:
    Impeller of turbocharger rotates smoothly.


NG
REPLACE TURBOCHARGER SUB-ASSEMBLY
OK


7.CHECK ECM (VNTI VOLTAGE)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc P0234/34 Turbocharger / Supercharger Overboost Condition

  1. While idling the engine, check the waveform of the ECM connectors using an oscilloscope.

    OK:
    Tester Connection
    		Specified Condition
    E7-17 (VNTI) - E6-7 (E1)
    		Correct waveform is as shown
    Tool Setting
    		Condition
    5 V/DIV., 20 msec./DIV.
    		Idling with warm engine


NG
REPLACE ECM
OK


8.CHECK ECM (VNTO VOLTAGE)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc P0234/34 Turbocharger / Supercharger Overboost Condition

  1. While idling the engine, check the waveform of the ECM connectors using an oscilloscope.

    OK:
    Tester Connection
    		Specified Condition
    E7-10 (VNTO) - E6-7 (E1)
    		Correct waveform is as shown
    Tool Setting
    		Condition
    5 V/DIV., 20 msec./DIV.
    		Idling with warm engine


NG
REPLACE TURBO MOTOR DRIVER
OK


9.CHECK EGR VALVE ASSEMBLY


NG
REPLACE EGR VALVE ASSEMBLY
OK


10.INSPECT INTAKE AIR TEMPERATURE SENSOR
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc P0234/34 Turbocharger / Supercharger Overboost Condition

  1. Check the IAT sensor.

    1. Remove the MAF meter.

    2. Measure the resistance of the sensor.

      Standard resistance:
      Tester Connection
      		Condition
      		Specified Condition
      4 - 5
      		-20°C (-4°F)
      		13.6 to 18.4 kΩ
      20°C (68°F)
      		2.21 to 2.69 kΩ
      60°C (140°F)
      		0.49 to 0.67 kΩ


NG
REPLACE MASS AIR FLOW METER
OK

REPLACE ECM