GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2006 🢒 Monte Carlo 🢒 Engine 🢒 Engine Controls - 3.5L 🢒 DTC P0102 or P0103

DTC Descriptors

DTC P0102: Mass Air Flow (MAF) Sensor Circuit Low Frequency

DTC P0103: Mass Air Flow (MAF) Sensor Circuit High Frequency

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Ignition 1 Voltage

P0102

P0102

P0101

--

P0101, P0103

MAF Sensor Signal

P0102

P0102

P0102

P0102

P0101, P0103, P1101

Ground

--

P0102

P0102

--

P0102

Circuit/System Description

The mass airflow (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 MAF sensor has the following circuits:

    • An ignition 1 voltage circuit
    • A ground circuit
    • A signal circuit

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 airflow 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.

Conditions for Running the DTC
    • The engine is cranking or running.
    • The engine speed is more than 50 RPM.
    • The ignition 1 signal is more than 8 volts.
    • The throttle position (TP) indicated angle parameter is more than 3.5 percent.
    • The above conditions are met for more than 0.5 second.

Conditions for Setting the DTC

P0102

The control module detects that the MAF sensor frequency signal is less than 1,200 Hertz for more than 10 seconds.

P0103

The control module detects that the MAF sensor frequency signal is more than 11,500 Hertz for more than 10 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

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
    • 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 more 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.
    • A high resistance may cause a driveability concern before this DTC sets.

Reference Information

Schematic Reference

Fuel Injection Fuel Rail Assembly Replacement

Connector End View Reference

    •  Engine Controls Connector End Views
    •  Engine Control Module Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Special Tools Required

J 38522 Variable Signal Generator

Circuit/System Testing
  1. Inspect for any contamination, water intrusion, or debris on the sensing elements of the MAF sensor.
    2. ⇒If debris is present, clean the sensor. If the sensor cannot be cleaned, replace the sensor.
  2. Inspect the fuse in the ignition 1 voltage circuit of the MAF sensor.
    3. ⇒If the fuse is open, test the ignition 1 voltage circuit for a short to ground.
  3. Turn OFF the ignition. Disconnect the MAF/intake air temperature (IAT) sensor. Start the engine.
  4. Observe the MAF/IAT sensor with a scan tool for 0 Hz.
    5. ⇒If more than 0 Hz, turn OFF the ignition and inspect the harness for improper routing that is too close to any aftermarket accessories, secondary ignition wires, coils, solenoids, relays, or motors.
  5. Turn ON the ignition, with the engine OFF.
  6. Measure the battery voltage with a DMM.
  7. Connect a test lamp between the ignition 1 voltage circuit of the MAF sensor and a good ground.
  8. Connect the DMM to the probe of the test lamp and good ground, and measure for battery voltage.
    9. ⇒If not within 0.75 volt of battery voltage, repair the high resistance, open, or short to ground in the MAF sensor ignition 1 voltage circuit.
  9. Turn OFF the ignition and all accessories for 60 seconds to allow the control module to power down.
  10. Measure for 5 ohms of resistance from the ground circuit of the MAF sensor to a good ground with a DMM.
    11. ⇒If the resistance is more than 5 ohms, repair the high resistance or the open in the MAF sensor ground circuit.
  11. Turn ON the ignition, with the engine and all accessories OFF.
  12. Measure for 4.8-5.2 volts from the signal circuit of the MAF sensor to a good ground with a DMM.
    13. ⇒If more than 5.2 volts, test the circuit for a short to voltage. If the circuit tests normal, replace the control module.
    ⇒If less than 4.8 volts, test the circuit for an open or short to ground. If the circuit tests normal, replace the control module.

    Important: To set up the J 38522 variable speed generator, place the duty cycle to normal, the frequency to 5 K, and the signal switch to 5 volts.

  13. Turn OFF the ignition and connect the red lead of the J 38522 variable speed generator to the signal circuit at the MAF sensor harness connector and the black lead to good ground.
  14. Start the engine and observe the MAF sensor for 4,950-5,025 Hz with a scan tool.
    15. ⇒If the MAF sensor is not within the specified range, test for intermittent or poor connection at the control module. If tests normal, replace the control module.
    ⇒If the MAF sensor is within the specified range, test for intermittent or poor connection at the MAF sensor. If tests normal, replace the MAF sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Mass Airflow Sensor/Intake Air Temperature Sensor Replacement
    •  Control Module References for control module replacement, setup, and programming