P0102

2AZ-FXE ENGINE CONTROL: SFI SYSTEM: P0102,P0103: Mass or Volume Air Flow Circuit Low Input
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DESCRIPTION

The mass air flow meter sub-assembly is a sensor that measures the amount of air flowing through the throttle valve.

The hybrid vehicle control ECU uses this information to determine the fuel injection time and to provide the appropriate air fuel ratio.

Inside the mass air flow meter sub-assembly, 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 flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant temperature value of the hot wire, current is applied to these components in the mass air flow meter sub-assembly. The voltage level is proportional to the airflow through the sensor, and the hybrid vehicle control ECU 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 either of these DTCs are set, the hybrid vehicle control ECU enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the hybrid vehicle control ECU, 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 set, check the air-flow rate by entering the following menus: Powertrain / Engine and ECT / Data List / MAF.





MONITOR DESCRIPTION

If there is a defect in the mass air flow meter sub-assembly or an open or short circuit, the voltage level deviates from the normal operating range. The hybrid vehicle control ECU interprets this deviation as a malfunction in the mass air flow meter sub-assembly circuit and sets 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 hybrid vehicle control ECU sets a DTC.

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

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0102





P0103





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN





- Connect the Techstream to the DLC3.

- Turn the power switch on (IG) and turn the Techstream on.

- Clear the DTCs DTC Check / Clear.

- Turn the power switch off and wait for at least 30 seconds.

- Turn the power switch on (IG) and turn the Techstream on [A].

- Put the engine in inspection mode Component Tests and General Diagnostics.

- Start the engine.

- Idle the engine for 5 seconds [B].

- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.

- Read the pending DTC [C].

HINT
- If a pending DTC is outputs, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

- Input the DTC: P0102 or P0103.

- Check the DTC judgment result.





- If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] through [C] again.

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 hybrid vehicle control ECU records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

1. READ DTC OUTPUT

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

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

(e) Read the DTCs.

Result:





B -- CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
A -- Continue to next step.

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





(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reconnect the mass air flow meter sub-assembly connector.

NG -- INSPECT INTEGRATION RELAY (EFI MAIN RELAY)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Disconnect the hybrid vehicle control ECU 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 sub-assembly connector.

(e) Reconnect the hybrid vehicle control ECU connector.

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

4. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY





(a) Perform On-vehicle inspection On-Vehicle Inspection.

(b) Perform Inspection Inspection.

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

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

(2) Connect the Techstream to the DLC3.

(3) Turn the power switch on (IG).

(4) Turn the Techstream on.

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

(6) Blow air into the mass air flow meter sub-assembly and check that the intake air amount reading changes.

OK:

The reading changes.

NG -- REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Removal

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

5. CHECK HARNESS AND CONNECTOR (SENSOR GROUND)





(a) Disconnect the mass air flow meter sub-assembly connector.

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

Standard Resistance (Check for Open):





Text in Illustration





(c) Reconnect the mass air flow meter sub-assembly connector.

NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)

OK -- REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Removal

6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Disconnect the hybrid vehicle control ECU connector.

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

Standard Resistance (Check for Open):





(d) Reconnect the mass air flow meter sub-assembly connector.

(e) Reconnect the hybrid vehicle control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

7. INSPECT INTEGRATION RELAY (EFI MAIN RELAY)

(a) Inspect the integration relay Inspection.

NG -- REPLACE INTEGRATION RELAY Removal
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - MASS AIR FLOW METER SUB-ASSEMBLY)

(a) Remove the integration relay from the engine room relay block.

(b) Disconnect the integration relay connector.

(c) Disconnect the mass air flow meter sub-assembly connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(e) Reconnect the mass air flow meter sub-assembly connector.

(f) Reconnect the integration relay connector.

(g) Reinstall the integration relay.

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

9. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - IGCT RELAY) P0031

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

10. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - BODY GROUND) P0031

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI MAIN RELAY)