P0102
DTC P0102 or P0103
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 air flow and engine speed are very dependent on the battery pack state of charge. A small quantity of air entering the engine indicates a low load condition. A large quantity of air entering the engine indicates a high load condition.
The ECM applies 5 volts 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 MAF sensor is supplied power through the powertrain relay and a fuse. The ECM enables the MAF sensor only during engine run mode by grounding the MAF control circuit via a solid state devise called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM monitors the status of the driver. If the ECM detects an incorrect voltage for the commanded state of the driver, a MAF sensor supply voltage low side driver control circuit DTC is set.
Conditions for Running the DTC
* The engine is running for greater than 1 s.
* The engine speed is greater than 300 RPM.
* The ignition voltage is greater than 10 V.
* The above conditions are met for greater than 1 s.
* These DTCs run continuously when the above conditions are met.
Conditions for Setting the DTC
P0102
The ECM detects that the MAF sensor signal is less than 1,800 Hz or 0 g/s for greater than 30 s.
P0103
The ECM detects that the MAF Sensor is greater than 14,500 Hz or 108 g/s for greater than 30 s.
Action Taken When the DTC Sets
DTCs P0102 and P0103 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0102 and P0103 are Type B DTCs.
Diagnostic Aids
* Verify the integrity of the air induction system by inspecting for the following conditions:
- Any water intrusion in the induction system
- Any contamination or debris on the sensing elements of the MAF sensor
- Damaged components
* Verify that any electrical aftermarket devices are properly connected and grounded. Refer to Checking Aftermarket Accessories Checking Aftermarket Accessories.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Hybrid Modes of Operation Description Hybrid Modes of Operation Description
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.
For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Special Tools (Diagnostic Tools)
Circuit/System Verification
Note: To ensure a proper engine load, this diagnostic should be performed when the Hybrid/EV Battery Pack Charge Remaning parameter is at least 40%.
1. Observe the DTC information with a scan tool. Verify that DTC P121B and P121C are not set.
• If any of the DTCs are set, refer to DTC P121B or P121C P121B.
2. Vehicle ON, engine speed between 1,375 and 1,425 RPM, normal operating temperature. Verify the scan tool MAF Sensor parameter is between 1,800 and 2,400 Hz.
3. 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. Vehicle OFF, disconnect the harness connector at the B75B mass air flow/intake air temperature sensor.
2. Vehicle in Service Mode, test for 4.8-5.2 V between the signal circuit terminal 5 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
3. Verify that a test lamp illuminates between the ignition voltage circuit terminal 4 and ground.
• If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test or replace the components on the ignition voltage circuit.
4. Connect the test lamp between the MAF control circuit terminal 2 and the ignition voltage circuit terminal 4.
5. Vehicle in Service Mode, command the MAF Sensor Supply Voltage Low Side Driver ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
6. Vehicle OFF, connect the red lead of the J 38522 to the signal circuit terminal 5 at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
7. Set the J 38522 to the following specifications.
* Signal switch to 5 V
* Frequency switch to 5 KHz
* Duty Cycle switch to Normal
Note: The engine may run rough and stall.
8. Engine running, observe the scan tool MAF Sensor Hz parameter. The parameter should be between 4,950 and 5,025 Hz.
• If 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