Code No. P0106: Manifold Absolute Pressure Sensor Range/Performance Problem




OPERATION



  • A power voltage of 5 V is applied to the manifold absolute pressure sensor power terminal (terminal No. 1) from the engine-ECU (terminal No. 72) and earthed to the engine-ECU (terminal No. 31) from the manifold absolute pressure sensor (terminal No. 3).
  • The sensor signal is inputted to the engine-ECU (terminal No. 37) from the manifold absolute pressure sensor output terminal (terminal No. 2).

FUNCTION



  • The manifold absolute pressure sensor converts the manifold absolute pressure into a voltage signal and inputs the signal to the engine-ECU.
  • In response to the signal, the engine-ECU corrects the fuel injection amount, etc.

TROUBLE JUDGMENT


Check Conditions
  • Battery positive voltage is 8 - 16 V
  • 2 seconds later after the ignition switch has been in "ON" position or the engine has started up.
  • The following 3 conditions are formed:

  1. The engine cooling water temperature is from -5 to 80 °C.
  2. The air intake temperature is from -5 to 80 °C.
  3. The atmospheric pressure is from 76 to 120 kPa.
Judgment Criterion
  • When an idle state and an engine rotation speed of 2,000 r/min continue for three seconds, manifold absolute pressures are read and the difference between them goes under 800 Pa for 1 second.

PROBABLE CAUSES



  • Failed manifold absolute pressure sensor
  • Manifold absolute pressure sensor circuit harness damage or loose connector contact.
  • EGR cooler clogged.
  • EGR pipe (A, B) clogged.

  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 6: Manifold absolute pressure sensor

Q. Is the check result normal?
Go to Step 10.
Go to Step 2.

STEP 2. Connector check: A-105 manifold absolute pressure sensor connector

Q. Is the check result normal?

Go to Step 3.

Repair or replace the connector.

STEP 3. Perform voltage measurement at A-105 manifold absolute pressure sensor connector.


  • Use special tool test harness (MB991709) to connect connector, and measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 1 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?

Go to Step 5.

Go to Step 4.

STEP 4. Connector check: C-105 engine-ECU connector


Q. Is the check result normal?


    Check and repair harness between A-105 (terminal No. 1) manifold absolute pressure sensor connector and C-105 (terminal No. 72) engine-ECU connector.

    • Check power supply line for damage.

Repair or replace the connector.

STEP 5. Perform voltage measurement at A-105 manifold absolute pressure sensor connector.


  • Use special tool harness (MB991709) to connect connector, and measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.
OK: 0.5 V or less

Q. Is the check result normal?

Go to Step 7.

Go to Step 6.

STEP 6. Connector check: C-105 engine-ECU connector


Q. Is the check result normal?


    Check and repair harness between A-105 (terminal No. 3) manifold absolute pressure sensor connector and C-105 (terminal No. 31) engine-ECU connector.

    • Check earthing line for damage.

Repair or replace the connector.

STEP 7. Perform voltage measurement at A-105 manifold absolute pressure sensor connector.


  • Use special tool harness (MB991709) to connect connector, and measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: The voltage should be 0.7 - 1.2 V. When the accelerator pedal is quickly depressed from the idling state, the voltage temporarily rises.

Q. Is the check result normal?

Go to Step 8.

Replace the manifold absolute pressure sensor.

STEP 8. Perform voltage measurement at C-105 engine-ECU connector.



  • Measure engine-ECU terminal voltage.
  • Ignition switch: ON
  • Voltage between terminal No. 37 and earth.
OK: The voltage should be 0.7 - 1.2 V. When the accelerator pedal is quickly depressed from the idling state, the voltage temporarily rises.

Q. Is the check result normal?

Go to Step 9.


    Check and repair harness between A-105 (terminal No. 2) manifold absolute pressure sensor connector and C-105 (terminal No. 37) engine-ECU connector.

    • Check output line for damage.

STEP 9. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Go to Step 10.

Repair or replace the connector.

STEP 10. 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 11.
Replace the EGR cooler.

STEP 11. 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 12.
Replace the EGR pipe (A, B).

STEP 12. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 6: Manifold absolute pressure sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
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 DPF carries out the forcible DPF regeneration. (Refer to GROUP 17 - Emission Control - Diesel Particulate Filter (DPF) System - Forcible DPF Regeneration ).