Code No. P105: Barometric Pressure Sensor System <DOHC>

OPERATION

A power voltage of 5 V is applied to the barometric pressure sensor power terminal (terminal No. 1) of the air flow sensor connector from the engine-A/T-ECU (terminal No. 46) and earthed to the engine-A/T-ECU (terminal No. 16) from the air flow sensor (terminal No. 5).

The sensor signal is inputted to the engine-A/T-ECU (terminal No. 55) from the barometric pressure sensor output terminal (terminal No. 2) of the air flow sensor connector.

function

The barometric pressure sensor converts the barometric pressure into a voltage signal and inputs the signal to the engine-A/T-ECU.

In response to the signal, the engine-A/T-ECU corrects the fuel injection amount, etc.

TROUBLE JUDGMENT

Check Condition

2 seconds after the ignition switch has been placed in the "ON" position or the engine has started up.

Judgment Criterion

A sensor output voltage of 4.5 V or more (atmospheric pressure above 114 kPa or eqiovalent) for 4 seconds.

A sensor output voltage 0.2 V or less (atmospheric pressure below 5 kPa or eqiovalent).

PROBABLE CAUSE

Failed barometric pressure sensor

Open or short circuit in barometric pressure sensor circuit or loose connector contact

Failed engine-A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. MUT-II/III data list

Refer to Data list reference table .

Item 25: Barometric pressure sensor

Q: Is the check result normal?

YES: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points

).
NO: Go to Step 2

STEP 2. Connector check: B-08 air flow sensor connector

Q: Is the check result normal?

YES: Go to Step 3

.
NO: Repair.

STEP 3. Perform voltage measurement at B-08 air flow sensor connector.

Disconnect connector, and measure at harness side.

Ignition switch: ON

Voltage between terminal No. 1 and earth.

OK: 4.9 - 5.1 V

Q: Is the check result normal?

YES: Go to Step 9

.
NO: Go to Step 4

STEP 4. Perform voltage measurement at C-111 engine-A/T-ECU connector.

Measure engine-A/T-ECU terminal voltage.

Ignition switch: ON

Voltage between terminal No. 46 and earth.

OK: 4.9 - 5.1 V

Q: Is the check result normal?

YES: Go to Step 5

.
NO: Go to Step 6

STEP 5. Connector check: C-111 engine-A/T-ECU connector

Q: Is the check result normal?

YES:

Check and repair harness between B-08 (terminal No. 1) air flow sensor connector and C-111 (terminal No. 46) engine-A/T-ECU connector.

Check power supply line for open circuit.

NO: Repair.

STEP 6. Connector check: C-111 engine-A/T-ECU connector

Q: Is the check result normal?

YES: Go to Step 7

.
NO: Repair.

STEP 7. Check harness between B-08 (terminal No. 1) air flow sensor connector and C-111 (terminal No. 46) engine-A/T-ECU connector.

Check power supply line for short circuit.

Q: Is the check result normal?

YES: Go to Step 8

.
NO: Repair.

STEP 8. MUT-II/III data list

Refer to Data list reference table .

Item No. 25: Barometric pressure sensor

Q: Is the check result normal?

YES: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points

).
NO: Replace engine-A/T-ECU.

STEP 9. Perform voltage measurement at B-08 air flow sensor connector.

Disconnect connector, and measure at harness side.

Voltage between terminal No. 5 and earth.

OK: 2 Ω or less

Q: Is the check result normal?

YES: Go to Step 12

.
NO: Go to Step 10

STEP 10. Connector check: C-112 engine-A/T-ECU connector

Q: Is the check result normal?

YES: Go to Step 11

.
NO: Repair.

STEP 11. Check harness between B-08 (terminal No. 5) air flow sensor connector and C-112 (terminal No. 16) engine-A/T-ECU connector.

NOTE: Before checking harness, check intermediate connector C-16, and repair if necessary.

Check earthing line for open circuit or damage.

Q: Is the check result normal?

YES: Go to Step 8

.
NO: Repair.

STEP 12. Perform voltage measurement at B-08 air flow sensor connector.

Use special tool test harness (MB991709) to connect only terminal No. 1, No. 2 and No. 5, and then 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?

YES: Go to Step 14

.
NO: Go to Step 13

STEP 13. Connector check: C-111 engine-A/T-ECU connector

Q: Is the check result normal?

YES:

Check and repair harness between B-08 (terminal No. 1) air flow sensor connector and C-111 (terminal No. 46) engine-A/T-ECU connector.

Check power supply line for damage.

NO: Repair.

STEP 14. Perform voltage measurement at B-08 air flow sensor connector.

Use special tool test harness (MB991709) to connect only terminal No. 1, No. 2 and No. 5, and then measure at pick-up harness.

Ignition switch: ON

Voltage between terminal No. 5 and earth.

OK: 0.5 V or less

Q: Is the check result normal?

YES: Go to Step 16

.
NO: Go to Step 15

STEP 15. Connector check: C-112 engine-A/T-ECU connector

Q: Is the check result normal?

YES:

Check intermediate connector C-26, and repair if necessary. If intermediate connector is normal, check and repair harness between B-08 (terminal No. 5) air flow sensor connector and C-112 (terminal No. 16) engine-A/T-ECU connector.

Check earthing line for damage.

NO: Repair.

STEP 16. Perform voltage measurement at B-08 air flow sensor connector.

Use special tool test harness (MB991709) to connect only terminal No. 1, No. 2 and No. 5, and then measure at pick-up harness.

Ignition switch: ON

Voltage between terminal No. 2 and earth.

OK:

Altitude 0 m: 3.8 - 4.2 V

Altitude 600 m: 3.5 - 3.9 V

Altitude 1,200 m: 3.3 - 3.7 V

Altitude 1,800 m: 3.0 - 3.4 V

Q: Is the check result normal?

YES: Go to Step 19

.
NO: Go to Step 17

STEP 17. Connector check: C-111 engine-A/T-ECU connector

Q: Is the check result normal?

YES: Go to Step 18

.
NO: Repair.

STEP 18. Check harness between B-08 (terminal No. 2) air flow sensor connector and C-111 (terminal No. 55) engine-A/T-ECU connector.

Check output line for short circuit and damage.

Q: Is the check result normal?

YES: Replace air flow sensor.
NO: Repair.

STEP 19. Perform voltage measurement at C-111 engine-A/T-ECU connector.

Measure engine-A/T-ECU terminal voltage.

Ignition switch: ON

Voltage between terminal No. 55 and earth.

OK:

Altitude 0 m: 3.8 - 4.2 V

Altitude 600 m: 3.5 - 3.9 V

Altitude 1,200 m: 3.3 - 3.7 V

Altitude 1,800 m: 3.0 - 3.4 V

Q: Is the check result normal?

YES: Go to Step 21

.
NO: Go to Step 20

STEP 20. Connector check: C-111 engine-A/T-ECU connector

Q: Is the check result normal?

YES:

Check and repair harness between B-08 (terminal No. 2) air flow sensor connector and C-111 (terminal No. 55) engine-A/T-ECU connector.

Check output line for open circuit and damage.

NO: Repair.

STEP 21. Connector check: C-111 engine-A/T-ECU connector

Q: Is the check result normal?

YES: Go to Step 8

.
NO: Repair.


Code No. P105: Barometric Pressure Sensor System <DOHC>

OPERATION A power voltage of 5 V is applied to the barometric pressure sensor power terminal (terminal No. 1) of the air flow sensor connector from the engine-A/T-ECU (terminal No. 46) and earthed to the engine-A/T-ECU (terminal No. 16) from the air flow sensor (terminal No. 5). The sensor signal is inputted to the engine-A/T-ECU (terminal No. 55) from the barometric pressure sensor output terminal (terminal No. 2) of the air flow sensor connector.
function The barometric pressure sensor converts the barometric pressure into a voltage signal and inputs the signal to the engine-A/T-ECU. In response to the signal, the engine-A/T-ECU corrects the fuel injection amount, etc.
TROUBLE JUDGMENT Check Condition 2 seconds after the ignition switch has been placed in the "ON" position or the engine has started up. Judgment Criterion A sensor output voltage of 4.5 V or more (atmospheric pressure above 114 kPa or eqiovalent) for 4 seconds. Or A sensor output voltage 0.2 V or less (atmospheric pressure below 5 kPa or eqiovalent).
PROBABLE CAUSE Failed barometric pressure sensor Open or short circuit in barometric pressure sensor circuit or loose connector contact Failed engine-A/T-ECU
	DIAGNOSIS PROCEDURE

	STEP 1. MUT-II/III data list Refer to Data list reference table . Item 25: Barometric pressure sensor Q: Is the check result normal? YES: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points ). NO: Go to Step 2 .
	STEP 2. Connector check: B-08 air flow sensor connector
	Q: Is the check result normal? YES: Go to Step 3 . NO: Repair.
	STEP 3. Perform voltage measurement at B-08 air flow sensor connector.
	Disconnect connector, and measure at harness side. Ignition switch: ON Voltage between terminal No. 1 and earth. OK: 4.9 - 5.1 V Q: Is the check result normal? YES: Go to Step 9 . NO: Go to Step 4 .
	STEP 4. Perform voltage measurement at C-111 engine-A/T-ECU connector.
	Measure engine-A/T-ECU terminal voltage. Ignition switch: ON Voltage between terminal No. 46 and earth. OK: 4.9 - 5.1 V Q: Is the check result normal? YES: Go to Step 5 . NO: Go to Step 6 .
	STEP 5. Connector check: C-111 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Check and repair harness between B-08 (terminal No. 1) air flow sensor connector and C-111 (terminal No. 46) engine-A/T-ECU connector. Check power supply line for open circuit. NO: Repair.
	STEP 6. Connector check: C-111 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Go to Step 7 . NO: Repair.
	STEP 7. Check harness between B-08 (terminal No. 1) air flow sensor connector and C-111 (terminal No. 46) engine-A/T-ECU connector.
	Check power supply line for short circuit. Q: Is the check result normal? YES: Go to Step 8 . NO: Repair.
	STEP 8. MUT-II/III data list Refer to Data list reference table . Item No. 25: Barometric pressure sensor Q: Is the check result normal? YES: Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points ). NO: Replace engine-A/T-ECU.
	STEP 9. Perform voltage measurement at B-08 air flow sensor connector.
	Disconnect connector, and measure at harness side. Voltage between terminal No. 5 and earth. OK: 2 Ω or less Q: Is the check result normal? YES: Go to Step 12 . NO: Go to Step 10 .
	STEP 10. Connector check: C-112 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Go to Step 11 . NO: Repair.
	STEP 11. Check harness between B-08 (terminal No. 5) air flow sensor connector and C-112 (terminal No. 16) engine-A/T-ECU connector.
	NOTE: Before checking harness, check intermediate connector C-16, and repair if necessary. Check earthing line for open circuit or damage. Q: Is the check result normal? YES: Go to Step 8 . NO: Repair.
	STEP 12. Perform voltage measurement at B-08 air flow sensor connector.
	Use special tool test harness (MB991709) to connect only terminal No. 1, No. 2 and No. 5, and then 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? YES: Go to Step 14 . NO: Go to Step 13 .
	STEP 13. Connector check: C-111 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Check and repair harness between B-08 (terminal No. 1) air flow sensor connector and C-111 (terminal No. 46) engine-A/T-ECU connector. Check power supply line for damage. NO: Repair.
	STEP 14. Perform voltage measurement at B-08 air flow sensor connector.
	Use special tool test harness (MB991709) to connect only terminal No. 1, No. 2 and No. 5, and then measure at pick-up harness. Ignition switch: ON Voltage between terminal No. 5 and earth. OK: 0.5 V or less Q: Is the check result normal? YES: Go to Step 16 . NO: Go to Step 15 .
	STEP 15. Connector check: C-112 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Check intermediate connector C-26, and repair if necessary. If intermediate connector is normal, check and repair harness between B-08 (terminal No. 5) air flow sensor connector and C-112 (terminal No. 16) engine-A/T-ECU connector. Check earthing line for damage. NO: Repair.
	STEP 16. Perform voltage measurement at B-08 air flow sensor connector.
	Use special tool test harness (MB991709) to connect only terminal No. 1, No. 2 and No. 5, and then measure at pick-up harness. Ignition switch: ON Voltage between terminal No. 2 and earth. OK: Altitude 0 m: 3.8 - 4.2 V Altitude 600 m: 3.5 - 3.9 V Altitude 1,200 m: 3.3 - 3.7 V Altitude 1,800 m: 3.0 - 3.4 V Q: Is the check result normal? YES: Go to Step 19 . NO: Go to Step 17 .
	STEP 17. Connector check: C-111 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Go to Step 18 . NO: Repair.
	STEP 18. Check harness between B-08 (terminal No. 2) air flow sensor connector and C-111 (terminal No. 55) engine-A/T-ECU connector.
	Check output line for short circuit and damage. Q: Is the check result normal? YES: Replace air flow sensor. NO: Repair.
	STEP 19. Perform voltage measurement at C-111 engine-A/T-ECU connector.
	Measure engine-A/T-ECU terminal voltage. Ignition switch: ON Voltage between terminal No. 55 and earth. OK: Altitude 0 m: 3.8 - 4.2 V Altitude 600 m: 3.5 - 3.9 V Altitude 1,200 m: 3.3 - 3.7 V Altitude 1,800 m: 3.0 - 3.4 V Q: Is the check result normal? YES: Go to Step 21 . NO: Go to Step 20 .
	STEP 20. Connector check: C-111 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Check and repair harness between B-08 (terminal No. 2) air flow sensor connector and C-111 (terminal No. 55) engine-A/T-ECU connector. Check output line for open circuit and damage. NO: Repair.
	STEP 21. Connector check: C-111 engine-A/T-ECU connector
	Q: Is the check result normal? YES: Go to Step 8 . NO: Repair.