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For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Grand Prix 🢒 Engine 🢒 Engine Controls - 3.1L 🢒 DTC P0103 Mass Air Flow (MAF) Sensor Circuit High Frequency

Object Number: 388516 Size: MF
Cell 20: Power, Ground, MIL, and DLC
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The Mass Air Flow (MAF) sensor measures the amount of air which passes through it into the engine during a given time. The PCM uses the mass air flow information to monitor engine operating conditions for fuel delivery calculations. A large quantity of air entering the engine indicates an acceleration or high load situation, while a small quantity of air indicates deceleration or idle.

The MAF sensor produces a frequency signal which can be monitored using a scan tool. The frequency will vary within a range of around 2000 Hertz at idle to near 8,000 Hertz at maximum engine load. DTC P0103 will be set if the signal from the MAF sensor is above the possible range of a normally operating MAF sensor.

Conditions for Running the DTC
    •  The engine is running.
    •  Ignition voltage greater than 8.0 volts.

Conditions for Setting the DTC
    •  MAF signal frequency is above 11,500 Hertz (11.5 kHz).
    •  Above conditions present for 0.5 seconds.

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

Conditions for Clearing the MIL/DTC
    • The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using a scan tool.

Diagnostic Aids

Check for the following conditions:

Misrouted harness Inspect the MAF sensor harness to ensure that it is not routed too close to high voltage wires such as spark plug leads.

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

    •  Poor terminal connection.
         Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Intermittents and Poor Connections Diagnosis , and Connector Repairs Wiring Systems.
    •  Damaged harness.
         Inspect the wiring harness for damage. If the harness appears to be OK, observe the sensor display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the sensor display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems.
    •  Inspect the PCM and the engine grounds for clean and secure connections.

If the DTC is determined to be intermittent, reviewing the Fail Records can be useful in determining when the DTC was last set.

Test Description

The numbers below refer to the step numbers on the Diagnostic Table:

  1. This step verifies that the problem is present at idle.

  2. A frequency reading with the MAF sensor connector disconnected indicates an Electro-Magnetic Interference (EMI) related fault or a poor connection.

  3. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Step

Action

Value(s)

Yes

No

1

Was the Powertrain on Board Diagnostic System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Start engine.
  2. With the engine idling, monitor MAF FREQUENCY display on the scan tool Eng 1 data list.

Is MAF FREQUENCY below the specified value?

11.5 kHz (11,500 Hertz)

Go to Step 4

Go to Step 3

3
  1. Turn the ignition on, engine off.
  2. Review and record scan tool Fail Records data.
  3. Operate vehicle within Fail Records conditions as noted.
  4. Using a scan tool, monitor Specific DTC info for DTC P0103.

Does scan tool indicate DTC P0103 failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4

  1. Turn the ignition off.
  2. Disconnect the MAF sensor connector.
  3. Start engine.
  4. Using a scan tool, monitor MAF FREQUENCY.

Does scan tool indicate a MAF FREQUENCY at the specified value?

0 Hz

Go to Step 5

Go to Step 7

5
  1. Check for a poor connection at the MAF sensor harness terminals.
  2. If a poor connection is found, replace faulty terminal(s). Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs .

Was a poor connection found?

--

Go to Step 10

Go to Step 6

6

Replace the MAF sensor. Refer to Mass Airflow Sensor Replacement .

Is the action complete?

--

Go to Step 10

--

7
  1. Check MAF harness for incorrect routing.
    2. •  Near secondary ignition wires or coils:
    •  Near other high voltage components (solenoids, relays, motors).
  2. If incorrect routing is found, correct harness routing.

Was a problem found?

--

Go to Step 10

Go to Step 8

8
  1. Check MAF signal circuit terminal connections at the PCM.
  2. If a poor connection is found, replace faulty terminal(s). Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs .

Was a poor connection found?

--

Go to Step 10

Go to Step 9

9

Important: :  The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

--

Go to Step 10

--

10
  1. Turn the ignition on, engine off.
  2. Review and record scan tool Fail Records data.
  3. Clear DTCs.
  4. Operate vehicle within Fail Records conditions as noted.
  5. Using a scan tool, monitor Specific DTC info for DTC P0103.

Does scan tool indicate DTC P0103 failed this ignition?

--

Go to Step 2

System OK