P0103
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 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 greater than 1 s.
* The ignition 1 signal is greater than 10 V.
* The above conditions are met for greater than 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 is less than 800 Hz (about 0.90 g/s) for greater than 10 s.
P0103
The ECM detects that the MAF Sensor Signal parameter is greater than 14,500 Hz (about 630 g/s) for greater than 10 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:
- Loose or improper installation
- Damaged components
- Any water intrusion in the induction system
- Any contamination or debris on the sensing elements of the MAF sensor
* A steady or intermittent high resistance of 15 ohm or greater on the ignition 1 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 sensor 1 signal circuit will cause the MAF sensor signal to be skewed or erratic. Additionally, it may cause a rapid fluctuation in the IAT Sensor 1 parameter.
* 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 Connector Views
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 Control Module References for scan tool information
Special Tools
* J 38522 Variable Speed Generator
* For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Tools and Equipment.
Circuit/System Verification
1. Engine idling, observe the scan tool MAF Sensor parameter. The reading should be between 2,000-3,900 Hz (about 2-8 g/s) depending on the engine coolant temperature (ECT).
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.
1. Engine idling
2. Perform the scan tool snapshot function.
3. Increase the engine speed slowly to 3,000 RPM and then back to idle.
4. Exit from the scan tool snapshot and review the data.
5. Observe the MAF Sensor parameter frame by frame with a scan tool.
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. Verify that the following DTCs are not set: P0685, P0690 or B1380.
• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Ignition OFF, disconnect the harness connector at the B75C multifunction intake air sensor.
3. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the ground circuit terminal 7 and ground.
• If greater 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 5 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
• If the circuit tests normal and the fuse is open, test all the components connected to the circuit and repair or replace as necessary.
5. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 6 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.
6. Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal 6 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
* Duty Cycle switch to 50 % (Normal)
* Frequency switch to 5 KHz
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 parameter is not within the specified range, replace the K20 ECM.
9. If all other circuits test normal, replace the B75C multifunction intake air sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Mass Airflow Sensor with Intake Air Temperature Sensor Replacement Service and Repair for multifunction intake air sensor replacement.
* Control Module References Control Module References for engine control module replacement, programming, and setup.