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 80 to 115 °C.
  2. The intake air 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 3 seconds, manifold absolute pressure are read and the difference between them goes under 800 Pa for 5 seconds.

FAIL-SAFE AND BACKUP FUNCTION



  • The pressure in the inlet manifold is controlled to be 100 kPa.
  • The EGR control is stopped (fully closed).
  • The fuel injection amount is restricted (Output restriction).
  • The open angle of the accelerator pedal is restricted.
  • The DPF regeneration is prohibited.
  • The throttle valve is opened (Electrical discontinuity).
  • The AS&G control is prohibited.

PROBABLE CAUSES



  • Vacuum hose clogged between manifold absolute pressure sensor and inlet manifold
  • Failed manifold absolute pressure sensor
  • Manifold absolute pressure sensor circuit harness damage or loose connector contact.
  • EGR cooler clogged.
  • EGR pipe (A, B) clogged.
  • EGR cooler by-pass valve clogged.
  • Failed engine-ECU

DIAGNOSTIC 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 11 .
Go to Step 2 .

STEP 2. Check for vacuum hose for clogs between manifold absolute pressure sensor and inlet manifold.

  • Check whether the vacuum hose is clogged between the manifold absolute pressure sensor and the inlet manifold, which is caused by dirt and the hose folded. Also check the inside inlet manifold and the nipple that can be possibly contaminated with dirt.

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

STEP 3. Connector check: B-14 manifold absolute pressure sensor connector

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

STEP 4. Perform voltage measurement at B-14 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 6 .
Go to Step 5 .

STEP 5. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?

    Check and repair harness between B-14 (terminal No. 1) manifold absolute pressure sensor connector and B-09 (terminal No. 72) engine-ECU connector.

    • Check power supply line for damage.
Repair or replace the connector.

STEP 6. Perform voltage measurement at B-14 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 8 .
Go to Step 7 .

STEP 7. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?

    Check and repair harness between B-14 (terminal No. 3) manifold absolute pressure sensor connector and B-09 (terminal No. 31) engine-ECU connector.

    • Check earthing line for damage.
Repair or replace the connector.

STEP 8. Perform voltage measurement at B-14 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 9 .
Replace the manifold absolute pressure sensor.

STEP 9. Perform voltage measurement at B-09 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 10 .

    Check and repair harness between B-14 (terminal No. 2) manifold absolute pressure sensor connector and B-09 (terminal No. 37) engine-ECU connector.

    • Check output line for damage.

STEP 10. Connector check: B-09 engine-ECU connector.

Q. Is the check result normal?
Go to Step 11 .
Repair or replace the connector.

STEP 11. 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 12 .
Replace the EGR cooler.

STEP 12. 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 13 .
Replace the EGR pipe (A, B).

STEP 13. Check on clogged EGR cooler by-pass valve.

  • Check whether the EGR cooler by-pass valve is being clogged or not.

Q. Is the check result normal?
Go to Step 14 .
Replace the EGR cooler by-pass valve.

STEP 14. 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.