DESCRIPTION
Refer to DTC P0100 (See page ES-116).
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, changing 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 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 MAF 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 MAF meter and sets the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
WIRING DIAGRAM
Refer to DTC P0100 (See page ES-118).
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the intelligent tester. 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.
1 CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0101)
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
(e) Read the DTCs.
Result
HINT: If any DTCs other than P0101 are output, troubleshoot those DTCs first.
GO TO DTC CHART (See page ES-56)
Disposal
HINT:
The tire pressure warning valve and transmitter is powered
by a lithium battery. When disposing of the tire pressure
warning valve and transmitter, remove the battery and
dispose of it correctly.
1. DISPOSE OF TIRE PRESSURE WARNING VALVE AND TRANSMITTER
(a) Use the tip of a screwdriv ...
Communication Error of Yaw Rate Sensor
DTC U0123 Communication Error of Yaw Rate Sensor
DESCRIPTION
This circuit detects the yaw rate of the vehicle and transmits its signal to
the skid control ECU and
distance control ECU.
DTC No.
DTC Detection Condition
Trouble Area
U0123
While the dynamic ...
Light Sensor Circuit Malfunction
DTC B1244 Light Sensor Circuit Malfunction
DESCRIPTION
This DTC is output when failure in the light sensor circuit is detected.
DTC No.
DTC Detection Condition
Trouble Area
B1244
Malfunction of automatic light control sensor
Open or short of a ...