Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
DTC Descriptors
DTC P0100: Mass Air Flow (MAF) Sensor CircuitDTC P0102: Mass Air Flow (MAF) Sensor Circuit Low Frequency
DTC P0103: Mass Air Flow (MAF) Sensor Circuit High Frequency
Diagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
Ignition 1 Voltage | P0100 | P0100 | P0100 | -- | P0101 |
MAF Sensor Signal | P0100 | P0102 | P0100 | P0102 | P0101 |
Low Reference | -- | P0102 | P0100 | -- | P0101 |
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, 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.
Conditions for Running the DTC
| • | The engine is operating. |
| • | The ignition voltage is more than 10.5 volts. |
| • | DTC P0100, P0102 and P0103 run continuously once the above conditions are met for 1 second. |
Conditions for Setting the DTC
P0100
| • | The ECM detects that the MAF sensor signal is 0.0 Hz. |
| • | The condition exists for 4 seconds or for a cumulative of 50 seconds. |
P0102
| • | The ECM detects that the MAF sensor signal is less than 1135 Hz. |
| • | The condition exists for 4 seconds or for a cumulative of 50 seconds. |
P0103
| • | The ECM detects that the MAF sensor signal is more than 15,152 Hz. |
| • | The condition exists for 4 seconds or for a cumulative of 50 seconds. |
Action Taken When the DTC Sets
DTCs P0100, P0102, and P0103 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0100, P0102, and P0103 are Type B DTCs.
Diagnostic Aids
| • | Inspect the harness of the MAF sensor to verify that it is not routed too close to the following components: |
| - | The secondary ignition wires or coils |
| - | Any solenoids |
| - | Any relays |
| - | Any motors |
| • | Inspect the hydro-carbon (HC) filter in the air cleaner assembly for ruptures that would leak charcoal into the air intake, contaminating the sensing element. |
| • | 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
Connector End View Reference
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- Engine idling for 1 minute, observe the DTC information with a scan tool. DTCs P0100, P0102 and P0103 should not set.
- If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the MAF sensor.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal B and ground.
- Test for less than 5 ohms between the ground circuit terminal C and the battery ground.
- Test for 4.89-5.10 volts between the signal circuit terminal A and the ground circuit terminal C.
- If all circuits test normal, replace the MAF sensor.
Notice: 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.
| ⇒ | If the test lamp does not illuminate, test the ignition 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. |
| ⇒ | If greater than the specified value, repair the ground circuit for an open/high resistance. |
| ⇒ | 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 ECM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for engine control module replacement, setup, and programming |
