P0103
2AZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0100,P0102,P0103: Mass or Volume Air Flow Circuit
DESCRIPTION
The Mass Air Flow (MAF) meter is a sensor that measures the amount of air flowing through the throttle valve.
The ECM (included in the hybrid vehicle control ECU) uses this information to determine the fuel injection duration 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 set, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine RPM 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 selecting the following menu items on the Techstream: Powertrain / Engine / Data List / All Data / MAF.
MONITOR DESCRIPTION
If there is a defect in the MAF meter or an open or short circuit, the voltage level deviates from the normal operating range. The ECM (included in the hybrid vehicle control ECU) interprets this deviation as a malfunction in the MAF meter 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 ECM 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
P0100:
P0100::
P0102:
P0102::
P0103:
P0103::
COMPONENT OPERATING RANGE
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
Read freeze frame data using the Techstream. The ECM (included in 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 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 power switch on (IG).
(c) Turn the tester on.
(d) Enter the following menus: Powertrain / Engine / DTC.
(e) Read the DTCs.
Result:
B -- CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
A -- Continue to next step.
2. INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
(a) Disconnect the C2 Mass Air Flow (MAF) meter connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage between the terminal of the wire harness side connector and body ground.
Standard voltage:
(d) Reconnect the MAF meter connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY - MASS AIR FLOW METER)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)
(a) Disconnect the C2 MAF meter connector.
(b) Disconnect the C64 hybrid vehicle control ECU connector.
(c) Measure the resistance.
Standard resistance (Check for open):
Standard resistance (Check for short):
(d) Reconnect the MAF meter connector.
(e) Reconnect the hybrid vehicle control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)
OK -- Continue to next step.
4. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY
(a) Perform On-vehicle Inspection Testing and Inspection.
(b) Inspection 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 to ON.
(4) Turn the Techstream on.
(5) Enter the following menus: Powertrain / Engine / Data List / MAF.
(6) Blow air to 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
OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal
5. CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
(a) Disconnect the C2 MAF meter connector.
(b) Measure the resistance.
Standard resistance:
NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)
OK -- REPLACE MASS AIR FLOW METER
6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)
(a) Disconnect the C2 MAF meter connector.
(b) Disconnect the C64 hybrid vehicle control ECU connector.
(c) Measure the resistance.
Standard resistance (Check for open):
Standard resistance (Check for short):
(d) Reconnect the MAF meter connector.
(e) Reconnect the hybrid vehicle control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - HYBRID VEHICLE CONTROL ECU)
OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal