P0100
DTC P0100 MASS OR VOLUME AIR FLOW CIRCUITCIRCUIT DESCRIPTION
DTC Detecting Condition:
The MAF (Mass Air Flow) sensor measures the amount of air flowing through the throttle valve. The ECM uses this information to determine the fuel injection time and provide a proper air-fuel ratio. Inside the MAF sensor, there is a heated platinum wire exposed to the flow of intake air.
By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incoming air cools the wire and an internal thermistor, changing their resistance. To maintain a constant current value, the ECM varies the voltage applied to these components in the MAF sensor. The voltage level is proportional to the airflow through the sensor and the ECM interprets this voltage as the intake air amount. The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
HINT: After confirming DTC "P0100, P0102 or P0103", use the hand-held tester or the OBD II scan tool to confirm the mass air flow ratio from the "DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL".
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
Component Operating Range:
If there is a defect in the sensor or an open or short circuit, the voltage level will deviate outside the normal operating range. The ECM interprets this deviation as a defect in the MAF sensor and sets a DTC.
Example:
When the sensor voltage output is less than 0.2 V or more than 4.9 V and if either condition continues more than 3 sec.
Wiring Diagram:
Step 1 - 2:
Step 3 - 4:
Step 5 - 6:
Step 7:
INSPECTION PROCEDURE
HINT: Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:
By putting the vehicle's ECM in the check mode, the 1 trip detection logic is possible instead of the 2 trip detection logic, and the sensitivity to detect faults is increased. This makes it easier to detect intermittent problems.
a. Clear the DTCs.
b. Set the check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and connector.