Diagnostic Instructions
DTC Descriptors
DTC P0101 11: Mass Air Flow Sensor Performance Above Maximum Threshold
DTC P0101 12: Mass Air Flow Sensor Performance Below Minimum Threshold
Circuit/System Description
The mass air flow (MAF) 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, greater 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.
Conditions for Running the DTC
| • | The battery voltage is greater than 8.5 volts |
| • | The engine speed is between 1,000-4,000 RPM |
Conditions for Setting the DTC
The ECM detects the MAF signal circuit is greater than, or less than, the normal operating range for less than 1 second.
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.
Diagnostic Aids
| • | Inspect the harness of the MAF sensor to verify that it is not routed too close to the following components: |
| • | Inspect for any contamination, water intrusion, or debris on the sensing elements of the MAF sensor. If debris is present, clean the sensor. If the sensor cannot be cleaned, replace the sensor. |
| • | A high resistance may cause a driveability concern before this DTC sets. |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running for 1 minute, observe the DTC information with a scan tool. DTC P0101 should not set.
- 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
- Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the B75 MAF sensor.
- Test for less than 5 Ω between the low reference circuit terminal 2 and ground.
| ⇒ | If greater than the specified range, repair 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.
- Install the MAIN fuse. Ignition ON, test for battery voltage between the ignition 1 circuit terminal 1 and ground.
| ⇒ | If less than the specified range, test the ignition 1 circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and
replace as necessary. |
- Test for 4.8-5.2 V between the signal circuit terminal 4 and ground.
| ⇒ | If less than the specified range, test the signal circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the K20 ECM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM. |
- If all circuits test normal, test or replace the B75 MAF sensor.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
