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. 80) and earthed to the engine-ECU (terminal No. 73) from the manifold absolute pressure sensor (terminal No. 3).
The sensor signal is inputted to the engine-ECU (terminal No. 52) 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 forned:

The engine cooling water temperature is from -5 to 80 °C.
The air intake temperature is from -5 to 80 °C.
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.

Failed engine-ECU

DIAGNOSIS PROCEDURE

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

Refer to Data List Reference Table .

Item 06: 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 ).

	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 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 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. 52 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 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. M.U.T.-III data list

Refer to Data List Reference Table .

Item 06: 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 - 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 ).