Buick Regal: DTC P0102 or P0103
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 Descriptors
DTC P0102
Mass Air Flow (MAF) Sensor Circuit Low Frequency
DTC P0103
Mass Air Flow (MAF) Sensor Circuit High Frequency
Diagnostic Fault Information
Typical Scan Tool Data
MAF Sensor
Circuit/System Description
The mass air flow (MAF) sensor is integrated with the multifunction intake
air sensor. The MAF sensor
is an air flow meter that measures the amount of air in the sensor bore. The
engine control module
(ECM) 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 ECM applies 5 V to the MAF sensor on the MAF sensor signal circuit. The
sensor uses the voltage
to produce a variable frequency signal based on the inlet air flow through the
sensor bore. The signal
varies with engine load and is displayed by the scan tool as Hertz (Hz) and
grams per second (g/s).
Ignition voltage and ground circuits are also supplied to the multifunction
intake air sensor's internal
circuits for these sensors:
- Intake Air Temperature (IAT) sensor 2
- Humidity sensor
- MAF sensor
The multifunction intake air sensor houses the following:
- IAT sensor 1
- IAT sensor 2
- Humidity sensor
- MAF sensor
- BARO pressure sensor
Conditions for Running the DTC
- The engine is running for at least 1 s.
- The engine speed is at least 300 RPM.
- The ignition signal is at least 11 V.
- The above conditions are met for at least 1 s.
- The DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
P0102
The ECM detects that the MAF Sensor signal parameter is less than 500 Hz
(about 0.25 g/s) for at least
250 cylinder firing events.
P0103
The ECM detects that the MAF Sensor signal parameter is at least 11, 000 Hz
(about 328 g/s) for at least
250 cylinder firing events.
Action Taken When the DTCs Set
DTCs P0102 and P0103 are Type B DTCs.
Conditions for Clearing the MIL/DTCs
DTCs P0102 and P0103 are Type B DTCs.
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. Engine idling, observe the scan tool MAF Sensor parameter. The reading
should be between 2.5 -
5.5 g/s.
- If not between 2.5 - 5.5 g/s
Refer to Circuit/System Testing.
- Go to next step: If between 2.5 - 5.5 g/s
2. 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.
- The MAF Sensor parameter does not change smoothly and gradually
Refer to Circuit/System Testing.
- Go to next step: The MAF Sensor parameter changes smoothly and
gradually
3. 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.
4. Verify the DTC does not set.
Refer to Circuit/System Testing.
- Go to next step: If the DTC does not set
5. All OK
Circuit/System Testing
NOTE: You must perform the Circuit/System Verification before
proceeding with
Circuit/System Testing.
1. Ignition OFF, disconnect the harness connector at the B75C Multifunction
Intake Air sensor.
2. Test for less than 2 Ω between the ground circuit terminal 7 and ground.
- Ignition OFF. Disconnect the sensor chassis ground.
- 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 chassis
ground connection.
- Go to next step: If less than 2 Ω
3. 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
4. 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
5. 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.
6. 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+
7. 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)
8. Engine idling, verify the scan tool MAF Sensor parameter is 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.
9. 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:
The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag
and knee airbag if the system
determines that an infant is present
in a child restraint. If a child restraint
has been installed and the on
indicator is lit:
1. Turn the vehicle off.
2. Remove the child
SPECIFICATIONS
FASTENER SPECIFICATIONS
Reusable Threaded Fastener Tightening Specifications
NOTE:
All fasteners listed in this table can be reused after removal.
SCHEMATIC WIRING DIAGRAMS
ANTILOCK BRAKE SYSTEM WIRING SCHEMATICS
Power, Ground, Serial Data, and Subsystem References
Wheel Speed Senso