P0101

2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0101: Mass or Volume Air Flow Circuit Range / Performance Problem
P0101 - Mass or Volume Air Flow Circuit Range / Performance Problem

DESCRIPTION

Refer to DTC P0100 P0100.





MONITOR DESCRIPTION

The mass air flow 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 mass air flow 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, changing their resistance. To maintain a constant current value, the ECM varies the voltage applied to these components of the mass air flow meter. The voltage level is proportional to the air flow through the sensor, and the ECM uses it to calculate the intake air volume.

If there is a defect in the sensor, or an open or short in the circuit, the voltage level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the mass air flow meter and sets the DTC.

Example:

- If the voltage is more than 2.2 V, or less than 0.73 V while idling, the ECM determines that there is a malfunction in the mass air flow meter and sets the DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM

Refer to DTC P0100 P0100.

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 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. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0101)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the tester on.

(d) Select the following menu items: Powertrain / Engine and ECT / Trouble Code.

(e) Read the DTCs.

Result:





HINT
If any DTCs other than P0101 are output, troubleshoot those DTCs first.

B -- REPLACE MASS AIR FLOW METER Components

A -- GO TO DTC CHART Engine Control System - SFI System