DTC P0101 Mass Air Flow (MAF) Sensor Performance. Cadillac Eldorado 2000

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2000 🢒 Eldorado 🢒 Engine 🢒 Engine Controls - 4.6L 🢒 DTC P0101 Mass Air Flow (MAF) Sensor Performance

Engine Controls Component Views
MAF Sensor, EVAP Components and EGR Valve
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 greater than a calibrated amount, DTC P0101 will set.

Conditions for Running the DTC

•	No TP sensor, MAP sensor, or system voltage DTCs are set.

•	Ignition voltage between 11 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 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 greater 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 Intermittent Conditions in Symptoms.

Test Description

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

The MAF system performance or rationality diagnostic uses the MAP sensor signal along with other inputs in order to calculate an expected airflow rate. The PCM then compares the expected flow rate to the actual measured airflow from the MAF sensor. The first few steps of this table verify that the MAP sensor is working properly. Correct any MAP sensor DTCs first. Refer to DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage if the MAP sensor voltage is less than 0.8 volts. Refer to DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage if the MAP sensor voltage is more than 4.0 volts.

Release the retaining tabs in order to remove the MAP sensor.

Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For any test that requires probing the PCM or component harness connectors, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents any damage to the harness connector terminals. Refer to Using Connector Test Adapters in Wiring Systems.

Any un-metered air causes this DTC to set. Check the PCV system for vacuum leaks. Also inspect the dip stick for being pulled out. Check the oil fill cap for being loose.

This step verifies the signal circuit from the MAF sensor electrical connector to the PCM.

This step verifies whether a ground and B+ circuit is available.

This step checks the signal circuit for an open.

This step checks the signal circuit for a short to B+.

Step

Action

Value(s)

Yes

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

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

If any MAP sensor DTCs are set, refer to the applicable DTC before proceeding.

Idle the engine.
Monitor the MAP sensor voltage parameter using a scan tool.

Is the MAP sensor voltage outside of the specified range?

0.8-4V

Go to DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage or DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage

Go to Step 3

Turn OFF the ignition.
Remove the MAP sensor from the intake manifold leaving the electrical harness connected.
Connect a hand operated vacuum pump to the MAP sensor.
Turn ON the ignition leaving the engine OFF.
Observe or record the MAP sensor display while slowly applying vacuum up to 20 inches Hg as indicated on the pump gauge. Each 1 inch of vacuum applied should result in a 3 to 4 kPa drop in the MAP sensor value on the scan tool and the value should change smoothly with each increase in vacuum.

Did the MAP sensor value change smoothly through the entire range of the test without any erratic readings?

Go to Step 4

Go to Step 19

Apply 20 inches Hg vacuum to the MAP sensor.

Is the MAP sensor reading on the scan tool the same or less than the specified value?

34 kPa

Go to Step 5

Go to Step 19

Disconnect the vacuum source from the MAP sensor.

Does the MAP sensor reading return to the original value that was observed in step 3?

Go to Step 6

Go to Step 19

Turn ON the ignition leaving the engine OFF.
Review the Freeze Frame and/or Failure Records data for this DTC and observe the parameters.
Turn OFF the ignition for 15 seconds.
Re-install the MAP sensor.
Start the engine.
Operate the vehicle within the conditions required for this diagnostic to run, and as close to the conditions recorded in the Freeze Frame/Failure Records as possible. Special operating conditions that you need to meet before the PCM will run this diagnostic, where applicable, are listed in Conditions for Running the DTC.
Select the Diagnostic Trouble Code (DTC) option, the Specific DTC option, then enter the DTC number using the scan tool.

Does the scan tool indicate that this diagnostic failed this ignition?

Go to Step 7

Go to Diagnostic Aids

Check for the following conditions:

•	Objects blocking the MAF sensor inlet screen

•	Intake manifold vacuum leaks

•	Vacuum leaks at the throttle body

•	Crankcase ventilation valve faulty, missing, or incorrectly installed

If you find a condition, repair as necessary.

Did you find and correct the condition?

Go to Step 21

Go to Step 8

Turn OFF the ignition.
Disconnect the MAF sensor connector.
Turn ON the ignition leaving the engine OFF.
Measure the voltage between the MAF sensor signal circuit and the battery ground using the DMM J 39200 .

Is the voltage near the specified value?

Go to Step 9

Go to Step 10

Connect the test lamp J 35616-200 between the MAF sensor ignition positive voltage and the ground circuit at the MAF sensor harness connector.

Is the test lamp illuminated?

Go to Step 13

Go to Step 12

Is the voltage less than the specified value?

4.5V

Go to Step 14

Go to Step 11

Turn OFF the ignition.
Disconnect the PCM connector C2 located on the opposite side of the manufacturer's logo. Refer to Powertrain Control Module Replacement/Programming .
Turn ON the ignition leaving the engine OFF.
Measure the voltage between the MAF sensor signal circuit at the PCM connector and ground.

Does the voltage measure near the specified value?

Go to Step 20

Go to Step 17

Connect the test lamp J 35616-200 between the MAF sensor ignition positive voltage circuit and the battery ground.

Is the test lamp illuminated?

Go to Step 15

Go to Step 16

Check for a poor connection at the MAF sensor.
If you find a poor connection, replace the faulty terminal(s). Refer to Connector Repairs in Wiring Systems.

Did you find a poor connection?

Go to Step 21

Go to Step 18

Check the MAF sensor signal circuit between the PCM and the MAF sensor for the following:

•	An open circuit

•	A short to ground

•	A short to the MAF sensor ground circuit.

Repair the circuit if the MAF sensor signal circuit is open or shorted. Refer to Wiring Repairs in Wiring Systems.

Did you find the MAF sensor signal circuit open or shorted?

Go to Step 21

Go to Step 20

Locate and repair the open in the ground circuit to the MAF sensor. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 21

Locate and repair the open in the ignition positive voltage circuit to the MAF sensor. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 21

Locate and repair the short to voltage in the MAF sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 21

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

Is the action complete?

Go to Step 21

Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement .

Is the action complete?

Go to Step 21

Important:: Program the replacement PCM. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

Go to Step 21

Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
Idle the engine at the normal operating temperature.
Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

Go to Step 22

Go to Step 2

Select the Capture Info option and the Review Info option using the scan tool.

Does the scan tool display any DTCs that you have not diagnosed?

Go to the applicable DTC table

System OK