• | 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 provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Ignition 1 Voltage | P0102 | P0102 | P0102 | -- | P0101 |
MAF Sensor Signal | P0102 | P0102 | P0102 | P0103 | P0101 |
Low Reference | -- | P0103 | P0103 | -- | P0101 |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine operating in Closed Loop. Parameter Normal Range: 3-4 g/s, 0.6-0.9 V | |||
Ignition 1 Voltage | 0.g/s, 0 V | 0 g/s, 0 V | -- |
MAF Sensor Signal | 0 g/s, 0 V | 0 g/s, 0 V | 196 g/s, 5 V |
Low Reference | 3.9 g/s, 0.7 V | 196 g/s, 5 V | * |
* Internal ECM damage may occur if the circuit is shorted to B+. |
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. A small quantity of air entering the engine indicates a deceleration or idle condition. A large quantity of air entering the engine indicates an acceleration or high load condition. The control module applies a voltage to the sensor on the signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies within a range of near 2,000 Hertz at idle to near 10,000 Hertz at maximum engine load.
• | DTCs P0102, P0103, P0107, P0108, P0121, P0122, P0123, P0221, P0222, or P0223 are not set. |
• | The engine speed is between 512-4,512 RPM. |
• | The TP indicated angle is between 15-100 percent. |
• | DTC P0101 runs continuously once the above conditions are met. |
• | The engine speed is greater than 512 RPM. |
• | The TP indicated angle is less than 1 degrees. |
• | DTCs P0102 and P0103 run continuously once the above conditions are met. |
The engine control module (ECM) detects that the MAF sensor signal is not within a predetermined range of the calculated MAF value.
The ECM detects that the MAF sensor signal is less than 0.2 volt.
The ECM detects that the MAF sensor signal is greater than 4.9 volts.
• | DTC P0101 is a Type B DTC. |
• | DTCs P0102 and P0103 are Type A DTCs. |
• | DTC P0101 is a Type B DTC. |
• | DTCs P0102 and P0103 are Type A DTCs. |
• | 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 |
• | A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 3-10 g/s at idle to 150 g/s or greater at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system. |
• | 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. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If less than B+, repair the open/high resistance in the ignition 1 voltage circuit. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If the signal voltage did not increase with air flow, replace the MAF sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Mass Air Flow (MAF) Sensor Replacement |
• | Control Module References for control module replacement, setup, and programming |