P0101
DTC P0101
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0101
- Mass Air Flow (MAF) Sensor Performance
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The control module uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads. The MAF sensor is a hot wire design. A platinum hot wire and a thermistor are located in the intake air bypass passage of the MAF sensor housing. The temperature of the platinum hot wire is affected by exposure to air flow and by exposure to air temperature. The platinum hot wire is maintained at a set temperature by controlling the current flow through the wire. The MAF sensor converts the changes in current flow to a voltage signal. The voltage signal from the MAF sensor enables the PCM to detect changes in air density and changes in air volume.
Conditions for Running the DTC
* DTCs P0100, P0102, P0103, P0115, P0117, P0118, P0120 P0122, P0123, P0125, P0220, P0222, P0223, P0335, P0340, P0341, P2135 are not set.
* The engine is running.
* The ignition voltage is greater than 10.5 volts.
* The engine coolant temperature (ECT) is greater than 75°C (167°F).
* DTC P0101 runs continuously when the above conditions are met.
Conditions for Setting the DTC
* The engine speed is less than 2,000 RPM.
* The throttle valve is closed.
* The MAF sensor output is greater than 2.2 volts.
* The condition exists for greater than 10 seconds.
OR
* The engine speed is greater than 300 RPM.
* The throttle position (TP) sensor input is greater than 0.63 volt.
* The MAF sensor output is less than 0.93 volt.
* The condition exists for greater than 10 seconds.
Action Taken When the DTC Sets
DTC P0101 is a Type B DTC.
Conditions for Clearing the DTC
DTC P0101 is a Type B DTC.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Engine running for 1 minute, verify the MAF sensor scan tool parameter is between 1.5-5.0 g/s.
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.
Circuit/System Testing
1. Verify the following conditions do not exist:
* Objects blocking the MAF sensor inlet
* Intake manifold vacuum leaks
* Throttle body vacuum leaks
* A faulty, missing, or incorrectly installed positive crankcase ventilation (PCV) valve
* Vacuum hose splits, kinks, or incorrect connections
* Excessive coking or carbon deposits of the throttle valve and throttle bore
• If you find any of the above conditions, repair as necessary.
2. If all conditions test normal, test or replace the MAF sensor.
Component Testing
1. Ignition OFF, disconnect the harness connector at the MAF sensor.
2. Install jumper wires between the MAF sensor and the appropriate harness connector terminals.
3. Ignition ON, test for voltage between the MAF sensor signal circuit and ground while blowing air through the MAF sensor.
• If the MAF signal voltage does not increase with air flow, replace the MAF sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Mass Airflow Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for control module replacement, setup, and programming