P0101
2ZR-FE ENGINE CONTROL: SFI SYSTEM: P0101: Mass Air Flow Circuit Range / Performance Problem
P0101 - Mass Air Flow Circuit Range / Performance Problem
DESCRIPTION
Refer to DTC P0102 P0102.
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, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to 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.
The ECM monitors the average engine load value ratio to check the mass air flow meter for malfunctions. The average engine load value ratio is obtained by comparing the average engine load calculated from the mass air flow 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 the DTC is set.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
WIRING DIAGRAM
Refer to DTC P0102 P0102.
CONFIRMATION DRIVING PATTERN
HINT
Performing this confirmation pattern will activate the mass air flow performance monitor.
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear DTCs DTC Check / Clear.
5. Switch the ECM from normal mode to check mode using the Techstream.
6. Start the engine, and warm it up until the engine coolant temperature reaches 70°C (158°F) or higher.
7. Drive the vehicle at approximately 62 mph (100 km/h) for 20 seconds or more.
8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
9. Read the DTCs.
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 to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs.
Result:
HINT
If any DTCs other than P0101 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART Engine Control System - SFI System
A -- Continue to next step.
2. CHECK INTAKE SYSTEM
(a) Check the intake system for vacuum leaks Testing and Inspection.
OK:
No leaks from intake system.
NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.
3. CHECK PCV HOSE CONNECTIONS
(a) Check the PCV hose connections Testing and Inspection.
OK:
PCV hose is connected correctly and is not damaged.
NG -- REPAIR OR REPLACE PCV HOSE
OK -- REPLACE MASS AIR FLOW METER Removal