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P0102





2AR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0102, P0103: Mass or Volume Air Flow Circuit Low Input


DESCRIPTION

The Mass Air Flow (MAF) meter is a sensor that measures the amount of air flowing through the throttle valve. The ECM uses this information to determine the fuel injection time and to provide the appropriate air-fuel ratio.

Inside the MAF meter, there is a heated platinum wire which is exposed to the flow of intake air. By applying a specific electrical current to the wire, the ECM heats it to a given temperature. The flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to the wire and internal thermistor. The voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake air volume.

The circuit is constructed so that the platinum hot wire and the temperature sensor create a bridge circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the predetermined temperature.

HINT
When any of these DTCs is stored, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine speed and throttle valve position. Fail-safe mode continues until a pass condition is detected.









HINT
When any of these DTCs are output, check the air-flow rate using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.





MONITOR DESCRIPTION

If there is a defect in the Mass Air Flow (MAF) meter or an open or short circuit, the voltage level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the MAF meter circuit and stores a DTC.

Example:

When the sensor output voltage remains below 0.2 V or higher than 4.9 V for more than 3 seconds, the ECM stores a DTC.

If the malfunction is not repaired successfully, a DTC is stored 3 seconds after the engine is next started.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0102:





P0103:





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on [A].

6. Start the engine.

7. Idle the engine for 5 seconds [B].

8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

9. Read the pending DTCs.

HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.

10. Run the engine at an engine speed of 4000 rpm for 5 seconds [D].

11. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [E].

12. Read the pending DTCs.

HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.

13. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

14. Input the DTC: P0102 or P0103.

15. Check the DTC judgment result.





HINT
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.
* If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [C] again.

16. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses of circuits related to this system before performing the following inspection procedure.

HINT
Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. READ VALUE USING TECHSTREAM (MASS AIR FLOW RATE)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.

(e) Read the values displayed on the Techstream.

Result





HINT
*: The value changes when the throttle valve is open or closed with the engine running.

B -- CHECK HARNESS AND CONNECTOR (SENSOR GROUND)

C -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
A -- Continue to next step.

2. INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)





(a) Disconnect the mass air flow meter connector.

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





(d) Reconnect the mass air flow meter connector.

NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY)
OK -- Continue to next step.

3. INSPECT MASS AIR FLOW METER

(a) Inspect output voltage.





(1) Disconnect the mass air flow meter connector.

(2) Apply battery voltage across terminals +B and E2G.

(3) Connect the positive (+) tester probe to terminal VG, and the negative (-) tester probe to terminal E2G.

(4) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





(5) Reconnect the mass air flow meter connector.

NG -- REPLACE MASS AIR FLOW METER Removal
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)





(a) Disconnect the mass air flow meter connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for open):





Standard Resistance (Check for short):





(d) Reconnect the mass air flow meter connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal

5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - INTEGRATION RELAY)





(a) Disconnect the mass air flow meter connector.

(b) Remove the integration relay (EFI MAIN relay) from the engine room No. 1 relay block.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for open):





Standard Resistance (Check for short):





(d) Reconnect the mass air flow meter connector.

(e) Reinstall the integration relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- GO TO ECM POWER SOURCE CIRCUIT ECM Power Source Circuit

6. CHECK HARNESS AND CONNECTOR (SENSOR GROUND)





(a) Disconnect the mass air flow meter connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





(c) Reconnect the mass air flow meter connector.

NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

OK -- REPLACE MASS AIR FLOW METER Removal

7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)





(a) Disconnect the mass air flow meter connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for open):





Standard Resistance (Check for short):





(d) Reconnect the mass air flow meter connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal
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