Description
Refer to dtc p0100 (see page es-86).
Monitor description
The 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 an 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 specific 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 of 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 ecm monitors the average engine load value ratio to check the maf meter for malfunctions. The average engine load value ratio is obtained by comparing the average engine load calculated from the maf meter output to the average engine load estimated from the driving conditions, such as the engine speed and the throttle opening angle. If the average engine load value ratio is below the threshold value, the ecm determines that the intake air volume is low, and if the average engine load value ratio is above the threshold value, the ecm determines that the intake air volume is high.
If this is detected in 2 consecutive driving cycles, the mil is illuminated and a dtc is set.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Wiring diagram
Refer to dtc p0100 (see page es-88).
Confirmation driving pattern
Hint:
Performing this confirmation pattern will activate the mass air flow performance monitor.
Inspection procedure
Hint:
Read freeze frame data using the intelligent tester. 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.
Hint:
If any dtcs other than p0101 are output, troubleshoot those
dtcs first.
Ok:
No leakage from air induction system.
Ok:
Pcv hose is connected correctly and is not damaged.
Replace mass air flow meter
Terminals of ecu
Check power steering ecu
Hint:
Measurements cannot be performed on the c connector
side of the power steering ecu.
Measure the voltage and resistance of the
connectors.
If the result is not as specified, the ecu may have a
malfunction. ...
Headlight relay
On-vehicle inspection
Remove headlight relay
Remove the headlight relay from the engine room
no. 2 Relay block.
Measure the resistance of the relay.
Standard resistance
If result is not as specified, replace the relay. ...
Theft deterrent system
Engine immobilizer system
The vehicle’s keys have built-in transponder chips that prevent
the engine from starting if a key has not been previously registered
in the vehicle’s on-board computer.
Never leave the keys inside the vehicle when you leave the vehicle.
This system is designed to ...