Buick Regal: DTC P0101
Diagnostic Instructions
- 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.
DTC Descriptor
DTC P0101
Mass Air Flow (MAF) Sensor Performance
Diagnostic Fault Information
Typical Scan Tool Data
MAF Sensor
Circuit Description
The intake flow rationality diagnostic provides the within-range rationality
check for the mass air flow
(MAF), manifold absolute pressure (MAP), and the throttle position sensors. This
is an explicit modelbased
diagnostic containing 4 separate models for the intake system.
The estimates of MAF and MAP obtained from this system of models and
calculations are then
compared to the actual measured values from the MAF, MAP, and the throttle
position sensors and to
each other to determine the appropriate DTC to fail.
Conditions for Running the DTCs
- DTC P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0116, P0117,
P0118, P0128, P0335, or
P0336 is not set
- The engine speed is between 575 - 6, 600 RPM.
- The engine coolant temperature (ECT) is between -7 to +129ºC (+19 to
+264ºF).
- The intake air temperature (IAT) is between -20 and +125ºC (-4 and
+257ºF).
- The DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
The engine control module (ECM) detects that the actual measured airflow from
the MAF, MAP, and
throttle position sensors is not within range of the calculated airflow that is
derived from the system of
models for greater than 2 s.
Action Taken When the DTC Sets
DTC P0101 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0101 is a Type B DTC.
Diagnostic Aids
- Any type of contamination on the MAF sensor heating elements will
degrade the proper operation
of the sensor. Certain types of contaminants act as a heat insulator, which
will impair the response
of the sensor to airflow changes. Water or snow can create the opposite
effect, and cause the signal
to increase rapidly.
- Certain aftermarket air filters may cause this DTC to set.
- Certain aftermarket air induction systems may cause this DTC to set.
- Modifications to the air induction system may cause this DTC to set.
Reference Information
Schematic Reference
Engine Controls Wiring Schematics (LTG)
Connector End View Reference
Component Connector End View Index
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Powertrain Component Views
Powertrain Component Views
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-38522-A Variable Signal Generator
For equivalent regional tools, refer to Special Tools (diagnostic tools) and
Special Tools (Mechanical Tools).
Circuit/System Verification
1. Ignition ON, verify that DTC P0641, P0651, P0697, or P06A3 is not set.
- If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further
diagnosis.
- Go to next step: If none of the DTCs are set
2. If you were sent here from DTC P0068, P0106, P0121, P0236, or P1101; refer
to Circuit/System
Testing.
3. Ignition ON, verify the scan tool Throttle Body Idle Airflow Compensation
parameter is less than
90 %.
Refer to Throttle Body Cleaning.
- Go to next step: If less than 90 %
4. Verify the scan tool Throttle Position Sensors 1 and 2 Agree/Disagree
parameter displays Agree
while performing the Throttle Sweep Test with a scan tool.
Refer to DTC P0121-P0123, P0222, P0223, P16A0-P16A2, or P2135 for further
diagnosis.
- Go to next step: If Agree
5. Determine the current vehicle testing altitude.
6. Verify the scan tool MAP Sensor pressure parameter is within the range
specified in the Altitude
Versus Barometric Pressure table.
- If the MAP Sensor parameter is not in range
Refer to DTC P0106 for further diagnosis.
- Go to next step: If the MAP Sensor parameter is within range
7. Verify the engine is equipped with a turbocharger.
- If not equipped with a turbocharger
Refer to Step 10.
- Go to next step: If equipped with a turbocharger
8. Verify the scan tool Boost Pressure Sensor parameter is within the range
specified in the Altitude
Versus Barometric Pressure table.
- If the Boost Pressure Sensor parameter is not in range
Refer to DTC P0236 for further diagnosis.
- Go to next step: If the Boost Pressure Sensor parameter is within
range
9. Engine idling.
10. Verify the scan tool Boost Pressure Sensor parameter increases with
accelerator pedal input.
- If the Boost Pressure Sensor parameter does not increase
Refer to DTC P0236 for further diagnosis.
- Go to next step: If the Boost Pressure Sensor parameter does increase
11. Verify the scan tool MAP Sensor pressure parameter is between 26 - 52 kPa
(3.8 - 7.5 PSI) and
changes with accelerator pedal input.
- If not between 26 - 52 kPa (3.8 - 7.5 PSI) or does not change
Refer to DTC P0106 for further diagnosis.
- Go to next step: If between 26 - 52 kPa (3.8 - 7.5 PSI) and changes
12. Verify the scan tool MAF Sensor g/s parameter changes smoothly and
gradually as the engine
speed is increased and decreased while performing the actions listed below.
- Engine idling
- Perform the scan tool snapshot function.
- Increase the engine speed slowly to 3, 000 RPM and then back to idle.
- Exit from the scan tool snapshot and review the data.
- Observe the MAF Sensor parameter frame by frame with a scan tool.
- If the MAF Sensor parameter does not change smoothly and gradually
Refer to Circuit/System Testing.
- Go to next step: If the MAF Sensor parameter changes smoothly and
gradually
13. Operate the vehicle within the Conditions for Running the DTC. You may
also operate the vehicle
within the conditions that you observed from the Freeze Frame/Failure Records
data.
14. Verify the DTC does not set.
Refer to Circuit/System Testing.
- Go to next step: If the DTC does not set
15. All OK
Circuit/System Testing
NOTE: You must perform the Circuit/System Verification before
proceeding with
Circuit/System Testing.
1. Verify the integrity of the entire air induction system by verifying that
none of the following
conditions exist:
- Any damaged components
- Improper operation of turbocharger wastegate actuator or bypass valve;
where equipped
- Improperly installed components
- Collapsed, restricted, or damaged components
- Loose clamps, cracks, or other damage
- An air flow restriction
- Restricted air filter
- Splits, kinks, leaks, or improper connections at the vacuum hoses
- Vacuum leaks at the intake manifold, MAP sensor, and throttle body
- Water intrusion
- Any snow or ice buildup, in cold climates
- Contamination of the Mass Air Flow sensor element
- If a condition is found
Repair or replace component as appropriate.
- Go to next step: If no condition is found
2. Ignition OFF, disconnect the harness connector at the B75C Multifunction
Intake Air sensor.
3. Test for less than 2 Ω between the ground circuit terminal 7 and ground.
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground
connection.
- Go to next step: If less than 2 Ω
4. Ignition ON, verify that a test lamp illuminates between the ignition
circuit terminal 5 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, remove the test lamp and remove the fuse for the ignition
voltage circuit.
- Test for less than 2 Ω in the ignition voltage circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, verify the fuse is not open and there is voltage
at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, remove the test lamp and remove the fuse for the ignition
voltage circuit.
- Test for infinite resistance between the ignition voltage circuit and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, test all components connected to the
ignition circuit, replace as
necessary.
- Go to next step: If a test lamp illuminates
5. Ignition ON, test for 4.8 - 5.2 volts between the signal circuit terminal
6 and ground.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Test for infinite resistance between the signal circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K20 Engine Control Module.
- Ignition OFF, disconnect the harness connector at the K20 Engine Control
Module.
- Ignition ON, test for less than 1 V between the signal circuit and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K20 Engine Control Module.
- Go to next step: If between 4.8 - 5.2 V
6. Determine if EL-38522-A Variable Signal Generator or equivalent is
available.
- EL-38522-A, Variable Signal Generator; or equivalent is not available
- Test or replace the B75C Multifunction Intake Air sensor.
- Operate the vehicle within the Conditions for Running the DTC. You may
also operate the
vehicle within the conditions that you observed from the freeze
frame/failure records data.
- Verify the DTC does not set.
Replace the K20 Engine Control Module.
- Go to next step: If no DTCs set
- All OK.
- Go to next step: EL-38522-A, Variable Signal Generator; or equivalent
is available
7. Ignition OFF, connect the leads of the EL-38522-A Variable Signal
Generator as follows:
- Red lead to the signal circuit terminal 6 at the harness connector
- Black leads to ground
- Battery voltage supply lead to B+
8. Set the EL-38522-A Variable Signal Generator to the following
specifications.
- Signal switch to 5 V
- Frequency switch to 5 kHz
- Duty Cycle switch to 50 % (Normal)
9. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool
MAF Sensor parameter
should be between 4, 950 - 5, 050 Hz.
- If not between 4, 950 - 5, 050 Hz.
Replace the K20 Engine Control Module.
- Go to next step: If between 4, 950 - 5, 050 Hz.
10. Test or replace the B75C Multifunction Intake Air sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic
procedure.
- Mass Airflow Sensor with Intake Air Temperature Sensor Replacement for
multifunction
intake air sensor replacement
- Control Module References for engine control module replacement,
programming, and setup
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
SEE MORE:
NOTE: Examples used in this article are general in nature and do not
necessarily
relate to a specific engine or system. Illustrations and procedures have
been chosen to guide mechanic through engine overhaul process.
Descriptions of processes of cleaning, inspection, assembly and machine
shop prac
WARNING:
Brake Dust Warning.
Preliminary Procedures
CAUTION:
Brake Caliper Supporting to Prevent Hose Damage Caution
NOTE:
Do NOT disconnect the brake hoses from the calipers.
1. Remove the brake caliper assembly and support with heavy mechanics wire.
Rear Brake
Caliper Replacement (GNC)Rear Brake