The mass air flow sensor is located in the air intake duct. The MAF sensor is an airflow meter that measures the amount of air that enters the engine. The MAF sensor uses a hot film that is cooled by air flowing past the sensing film as air enters the engine. The amount of cooling is proportional to the amount of the air flow. As the air flow increases, more current is required in order to maintain the hot film at a constant temperature. The engine control module (ECM) uses the MAF sensor in order to provide the correct fuel delivery for all operating conditions.

DTC P0101 is a Type B DTC.

DTC P0101 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Air Intake System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. Engine idling for 1 minute, observe the DTC information with a scan tool. DTC P0101 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Inspect for the following conditions:

•	An engine vacuum leak

•	An air leak in the intake air duct between the mass air flow sensor and the throttle body

•	A plugged or collapsed intake air duct

•	Objects that block the MAF sensor air inlet

•	An air filter element that is restricted

•	The hydro-carbon absorber, if equipped, in the air cleaner assembly for ruptures or deterioration.

•	A restricted throttle plate or for carbon build-up around the throttle plate

•	An unseated engine oil dip stick

•	A loose or missing engine oil fill cap

•	An over filled crankcase

⇒	If you find any of the above conditions, repair as necessary.

2. Ignition OFF, disconnect the harness connector at the B75 MAF sensor.
3. Ignition OFF, test for less than 5 Ω between the ground circuit terminal 2 and the battery ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

Caution: Do NOT use the low reference circuit in the component harness connector for this test. Damage to the control module may occur due to excessive current draw.

4. Ignition ON, load test the ignition circuit for B+ between terminal 4 and ground.

⇒	If less than the specified value, test the ignition circuit for an open/high resistance.

5. Test for 4.8-5.2 V between the signal circuit terminal A and the ground circuit terminal 5.

⇒	If less than the specified range, test the signal circuit for an open/high resistance or a short to ground. If the circuit/connections test normal, replace the K20 ECM.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the K20 ECM.

6. Ignition OFF, connect the red lead of the J 38522 Variable Signal Generator to the signal circuit terminal 5 at the B75 MAF sensor harness connector. Connect the battery voltage supply to B+, and ground the black lead.
7. Set the J 38522 Variable Signal Generator Signal switch to 5 V, the Frequency switch to 5K, and the Duty Cycle switch to Normal.
8. Ignition ON, observe the scan tool MAF Sensor frequency parameter. The parameter should be between 4,950-5,025 Hz.

⇒	If the parameter is not within the specified range, replace the K20 ECM.

9. If all circuits/connections test normal, replace the B75 MAF sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.