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DTC P0102 MASS OR VOLUME AIR FLOW CIRCUIT LOW INPUT

DTC P0102 MASS OR VOLUME AIR FLOW CIRCUIT LOW INPUT

DTC DETECTING CONDITION:


• Immediately at fault recognition

• GENERAL DESCRIPTION


TROUBLE SYMPTOM:


• Erroneous idling

• Engine stalls.

• Poor driving performance


Important

After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode .


WIRING DIAGRAM:


CONNECT Vehicle Diagnostic Interface OR THE OBD-II GENERAL SCAN TOOL, AND READ DATA.

Turn the ignition switch to OFF.

Connect the Vehicle Diagnostic Interface or OBD-II general scan tool to data link connector.

Turn the ignition switch to ON and Vehicle Diagnostic Interface or the OBD-II general scan tool switch to ON.

Start the engine.

Read the mass air flow sensor voltage using Vehicle Diagnostic Interface or OBD-II general scan tool.

Note
• Vehicle Diagnostic Interface

For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.

• OBD-II general scan tool

For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.


Is the measured value within 0.2 to 4.7 V?

Yes

• Even if malfunction indicator light lights up, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in the mass air flow sensor.

•
Note

In this case, repair the following:

• Open or ground short circuit in harness between mass air flow sensor and ECM connector

• Poor contact in mass air flow sensor or ECM connector



No


CHECK INPUT SIGNAL FOR ECM.

Measure the voltage between ECM connector and chassis ground while engine is idling.

Connector & terminal

(B136) No. 23 (+) — Chassis ground (−):

Is the measured value less than 0.2 V?

Yes


No


CHECK INPUT SIGNAL FOR ECM (USING Vehicle Diagnostic Interface).

Measure the voltage between ECM connector and chassis ground while engine is idling.

Shake the ECM harness and connector, while monitoring value of Vehicle Diagnostic Interface. Does the voltage change?

Yes

Repair the poor contact in ECM connector.


No

Contact Service Center.


CHECK POWER SUPPLY TO MASS AIR FLOW SENSOR.

Turn the ignition switch to OFF.

Disconnect the connector from mass air flow sensor.

Turn the ignition switch to ON.

Measure the voltage between mass air flow sensor connector and chassis ground.

Connector & terminal

(B3) No. 1 (+) — Chassis ground (−):

Is the voltage more than 5 V?

Yes


No

Repair the open circuit between mass air flow sensor and main relay.


CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW SENSOR CONNECTOR.

Turn the ignition switch to OFF.

Disconnect the connector from ECM.

Measure the resistance of harness between ECM and mass air flow sensor connector.

Connector & terminal

(B136) No. 23 — (B3) No. 3:

(B136) No. 31 — (B3) No. 2:

(B135) No. 35 — (B3) No. 5:

Is the measured value less than 1 Ω?

Yes


No

Repair the open circuit between ECM and mass air flow sensor connector.


CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW SENSOR CONNECTOR

Measure the resistance of harness between ECM and chassis ground.

Connector & terminal

(B136) No. 23 — Chassis ground:

(B136) No. 31 — Chassis ground:

(B135) No. 35 — Chassis ground:

Is the measured value more than 1 MΩ?

Yes


No

Repair the ground short circuit between ECM and mass air flow sensor connector.


CHECK POOR CONTACT

Check poor contact in mass air flow sensor connector.

Is there poor contact in mass air flow sensor connector?

Yes

Repair the poor contact in mass air flow sensor connector.


No

Replace the mass air flow and intake air temperature sensor.