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Home >> Buick >> 2011 >> Regal L4-2.0L Turbo >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0103

P0103




DTC P0102 or P0103 (LDK_LHU With Turbocharger) (2.0L With Turbocharger)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (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





Circuit/System Description

The mass air flow (MAF) sensor is integrated with the intake air temperature (IAT) sensor. The MAF sensor is an air flow meter that measures the amount of air entering the engine. The engine control module (ECM) uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads.

The ECM applies 5 V to the MAF sensor on the MAF sensor signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies in a range of near 1,700 Hz at idle to near 12,500 Hz at maximum engine load.

Conditions for Running the DTCs

* The engine is running.
* The engine speed is more than 300 RPM.
* The ignition 1 signal is more than 10.5 V.
* The above conditions are met for greater than 1 s.
* This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTC

P0102

The ECM detects that the MAF Sensor parameter is less than 1035 Hz for more than 0.5 s.

P0103

The ECM detects that the MAF Sensor parameter is greater than 15,152 Hz for more than 0.5 s.

Action Taken When the DTC Sets

* DTCs P0102, P0103 are Type B DTCs.
* The ECM will disable boost control and limit the system to mechanical boost only, resulting in a substantial decrease in engine power.

Conditions for Clearing the MIL/DTC

DTCs P0102, P0103 are Type B DTCs.

Diagnostic Aids

* The charge air cooler (CAC) is connected to the turbocharger and to the throttle body by flexible ductwork that requires the use of special high torque fastening clamps. These clamps cannot be substituted.
* A steady or intermittent high resistance of 15 ohm or greater on the ignition voltage circuit will cause the MAF sensor signal to be increased by as much as 60 g/s.
* Depending on the current ambient temperature, and the vehicle operating conditions, a MAF sensor signal circuit that is shorted to the IAT signal circuit will increase or decrease the MAF sensor signal that is interpreted by the ECM. Additionally it may cause a rapid fluctuation in the IAT Sensor parameter.
* Compare the MAF Sensor parameter to a known good vehicle under various operating conditions.

Reference Information
Schematic Reference

Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information
Special Tools

* J 38522 - Variable Signal Generator Variable Signal Generator
* For equivalent regional tools, refer to Special Tools (Tools and Equipment).

Circuit/System Verification

1. Verify that DTC P0641 or P0651 is not set.

• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).

2. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust (Restricted Exhaust).
3. Engine operating at idle, observe the scan tool MAF Sensor parameter. The reading should be between 1,700-2,600 Hz.
4. A wide open throttle (WOT) acceleration from a stop should cause the MAF Sensor parameter on the scan tool to increase rapidly. This increase should be from 2-6 g/s at idle to greater than 200 g/s at the time of the 1-2 shift.
5. Verify the proper operation of the MAP sensor. A skewed MAP sensor will cause the BARO value to be inaccurate. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) for DTC P0106 for further diagnosis.
6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Verify the integrity of the entire air induction system including all turbocharger components by inspecting for the following conditions:

* Loose or improper installation
* Water intrusion

2. Ignition OFF, disconnect the harness connector at the B75B mass air flow /intake air temperature sensor.
3. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm between the MAF sensor ground circuit terminal 2 or B and ground.

• If more than the specified range, test the ground circuit for an open/high resistance.

4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 3 or C and ground.

• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

5. Ignition ON, test for 4.8-5.2 V between the MAF signal circuit terminal 1 or A and ground.

• If less than the specified range, test the MAF signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
• If more than the specified range, test the MAF signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

6. Ignition OFF, connect the red lead of the J 38522 - Generator to the MAF signal circuit terminal 1 or A at the MAF sensor harness connector. Connect the battery voltage supply to B+. Connect the black lead to ground.
7. Set the J 38522 - Generator Signal switch to 5 V, the Frequency switch to 5 K, and the Duty Cycle switch to Normal.
8. Engine Idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,050 Hz.

• If the MAF Sensor parameter is not within the specified range, replace the K20 ECM.

9. If all circuits test normal, test or replace the B75B mass air flow /intake air temperature sensor.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Mass Airflow Sensor with Intake Air Temperature Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming

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