P0101

Diagnostic Chart (Part 1 Of 3):

Diagnostic Chart (Part 2 Of 3):

Diagnostic Chart (Part 3 Of 3):

Schematic:

CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) sensor is an air flow meter that measures the flow rate and density of the air entering the engine. The MAF sensor receives power and ground from circuits not supplied by the control module. The control module does apply a voltage to the sensor on the signal circuit. The sensor uses the voltage to produce a frequency based on inlet air flow through the sensor. A low air flow rate (such as engine idle) causes the MAF sensor to produce a low frequency signal. A high air flow rate (such as wide open throttle, or high load) causes the MAF sensor to produce a high frequency signal.

The PCM uses the MAF sensor signal to provide the correct fuel delivery for a wide range of engine speeds and loads. The PCM tests the sensor to verify the actual MAF signal. The PCM uses the MAP sensor, TP sensor, and the engine speed to calculate a predicted MAF value. Then, the PCM compares the actual MAF to the predicted MAF. If the difference between the actual MAF and the predicted MAF is greater than a calibrated amount, DTC P0101 will set.

CONDITIONS FOR RUNNING THE DTC
^ No TP sensor, MAP sensor, or system voltage DTCs are set.
^ Ignition voltage between 11 and 18 volts
^ Canister purge duty cycle is less than or equal to 90 percent.
^ Total EGR pintle valve movement is less than 90 percent.
^ Throttle angle is steady and less 48 percent.
^ MAP is steady and less than 59 kPa.

CONDITIONS FOR SETTING THE DTC
^ The difference between the actual MAF and the predicted MAF is greater than the calibrated amount.
^ The condition is present for at least 2.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
^ The PCM stores the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
For intermittent conditions, refer Intermittent Conditions in Symptoms. Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. The MAF system performance or rationality diagnostic uses the MAP sensor signal along with other inputs in order to calculate an expected airflow rate. The PCM then compares the expected flow rate to the actual measured airflow from the MAF sensor. The first few steps of this table verify that the MAP sensor is working properly. Correct any MAP sensor DTCs first. Refer to DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage if the MAP sensor voltage is less than 0.8 volts. Refer to DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage if the MAP sensor voltage is more than 4.0 volts. P0107 P0108
3. Release the retaining tabs in order to remove the MAP sensor.
6. Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For any test that requires probing the PCM or component harness connectors, use the Connector Test Adapter kit J 35616-A. Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Diagrams.
7. Any un-metered air causes this DTC to set. Check the PCV system for vacuum leaks. Also inspect the dip stick for being pulled out. Check the oil fill cap for being loose.
8. This step verifies the signal circuit from the MAF sensor electrical connector to the PCM.
9. This step verifies whether a ground and B+ circuit is available.
10. This step checks the signal circuit for an open.
11. This step checks the signal circuit for a short to B+.