P0102

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

DTC P0102 - Mass or Volume Air Flow Circuit Low Input

DTC P0103 - Mass or Volume Air Flow Circuit High 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 these components in the MAF meter. 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 are 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 / 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 less than 0.2 V, or more 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 procedure).

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 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 or more for 5 seconds [D].

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

12. Read 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 [E] again.

16. If the 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 for circuits related to this system before performing the following inspection procedure.

HINT
Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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 DTC OUTPUT

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read DTCs.

Result





B -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
A -- Continue to next step.

2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER)





(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:





Text in Illustration





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

3. 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:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. INSPECT MASS AIR FLOW METER

(a) Inspect the mass air flow meter, referring to the On-vehicle Inspection for Mass Air Flow Meter On-Vehicle Inspection.

(b) Inspect the mass air flow meter, referring to the Inspection Mass Air Flow Meter Inspection.

(c) Inspect the function of the mass air flow meter.

(1) Remove the mass air flow meter with the connector connected.

(2) Connect the Techstream to the DLC3.

(3) Turn the ignition switch to ON.

(4) Turn the Techstream on.

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

(6) Check that the mass air flow meter value changes when the engine is raced.

OK:

The reading changes.

NG -- REPLACE MASS AIR FLOW METER Removal

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 from the engine room relay block.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- CHECK ECM POWER SOURCE CIRCUIT ECM Power Source Circuit

6. 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:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. 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:





NG -- REPLACE ECM Removal

OK -- REPLACE MASS AIR FLOW METER Removal