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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 DTC 🢒 DTC P0101 Mass Air Flow (MAF) Sensor Performance

Object Number: 603340 Size: SF
Engine Controls Component Views
MAF and IAC
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The mass air flow (MAF) sensor is an air flow meter that measures the flow rate and density of the air entering the engine. The MAF sensor receives power and ground from circuits not supplied by the control module. The control module does apply a voltage to the sensor on the signal circuit. The sensor uses the voltage to produce a frequency based on inlet air flow through the sensor. A low air flow rate (such as engine idle) causes the MAF sensor to produce a low frequency signal. A high air flow rate (such as wide open throttle, or high load) causes the MAF sensor to produce a high frequency signal.

The PCM uses the MAF sensor signal to provide the correct fuel delivery for a wide range of engine speeds and loads. The PCM tests the sensor to verify the actual MAF signal. The PCM uses the MAP sensor, TP sensor, and the engine speed to calculate a predicted MAF value. Then, the PCM compares the actual MAF to the predicted MAF. If the difference between the actual MAF and the predicted MAF is more than a calibrated amount, DTC P0101 will set.

Conditions for Running the DTC
    • TP sensor, MAP sensor, or system voltage DTCs are not set.
    • Ignition voltage is between 11 volts and 18 volts.
    • Canister purge duty cycle is less than or equal to 90 percent.
    • Total EGR pintle valve movement is less than 90 percent.
    • Throttle angle is steady and less than 48 percent.
    • MAP is steady and less than 59 kPa.

Conditions for Setting the DTC
    • The difference between the actual MAF and the predicted MAF is more than the calibrated amount.
    • The condition is present for at least 2.5 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
    • The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data.

Conditions for Clearing the MIL/DTC
    • The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

For intermittent conditions, refer to Symptoms .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Since calculated MAF is based on many inputs, these DTCs should be diagnosed first.

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important: If any other DTCs are set, diagnose the other DTCs first.

Connect the scan tool.

Are any other DTCs set?

--

Diagnostic Trouble Code (DTC) List/Type

Go to Step 3

3

Observe the TP sensor display on the scan tool.

Is the TP sensor voltage below the specified value?

1V

Go to Step 4

Go to DTC P0121 TP Sensor Circuit Insufficient Activity

4
  1. Idle the engine.
  2. Monitor the MAP sensor voltage display on the scan tool.

Is the MAP sensor voltage with the specified range?

1-4V

Go to Step 5

Go to DTC P0106 Manifold Absolute Pressure (MAP) System Performance

5

  1. Check for vacuum leaks especially in the following areas:
    2. • The MAF sensor seal
    • The throttle body
    • The intake manifold
    • The EGR system
    • The PCV system
    • The brake booster system
  2. If a condition is found, repair as necessary.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 6

6
  1. Test for the following conditions:
    2. • A stuck or incorrect PCV valve
    • Unmetered air entering the engine -- Loose or missing oil dipstick or filler cap, loose or missing intake air duct
    • Open or poor MAP sensor ground
  2. If a condition is found, repair as necessary.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 7

7
  1. Review and record the scan tool Freeze Frame and fail records data.
  2. Operate the vehicle within the Freeze Frame and Fail Records conditions.
  3. Using the scan tool, monitor the Specific DTC Information for DTC P0101 until the test runs.

Does the scan tool indicate that DTC P0101 failed last test?

--

Go to Step 8

Go to Diagnostic Aids

8

Replace MAF sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .

Is the action complete?

--

Go to Step 9

--

9
  1. Review and record the scan tool fail records data.
  2. Clear the DTCs.
  3. Operate the vehicle within the parameters listed in the Conditions For Running the DTC.
  4. Using the scan tool, monitor the Specific DTC Information for DTC P0101 until the test runs.

Does the scan tool indicate that DTC P0101 passed?

--

System OK

Go to Step 2