P2199
DTC P2199
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 Descriptor
DTC P2199
- Intake Air Temperature (IAT) Sensor 1-2 Correlation
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The intake air temperature (IAT) sensor 1 is a variable resistor that measures the temperature of the air in the sensor bore. The engine control module (ECM) supplies 5 V to the IAT sensor 1 signal circuit and a ground for the IAT sensor 1 low reference circuit. The signal varies with inlet air temperature and is displayed by the scan tool as °C (°F).
The IAT sensor 2 produces a frequency signal based on the inlet air temperature very close to the humidity sensor within the sensor bore. The signal varies with inlet air temperature and is displayed by the scan tool as °C (°F) and Hertz (Hz). The ECM applies 5 V to the circuit. The signal circuit is shared by the IAT sensor 2 and the humidity sensor. Ignition voltage and ground circuits are also supplied to the multifunction intake air sensor's internal circuits for these sensors:
* 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 ignition is ON.
* Ignition 1 voltage is at least 11 V for at least 0.9 s.
* This DTC runs continuously within the enabling conditions.
Conditions for Setting the DTC
The ECM detects that the absolute difference between the IAT sensor 1 and the IAT sensor 2 temperatures is greater than 55°C (99°F) for longer than 5 s.
Action Taken When the DTC Sets
DTC P2199 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P2199 is a Type B DTC.
Diagnostic Aids
* With the ignition ON, the engine OFF, if the engine is cold, a properly functioning IAT sensor 2 will gradually increase the scan tool IAT Sensor 2 parameter. This is due to the heat that is generated by the multifunction intake air sensor heating elements.
* Depending on the ambient temperature, an IAT sensor 1 signal circuit that is shorted to the MAF sensor signal circuit can cause either a rapid fluctuation in the IAT Sensor 1 parameter or cause it to become stuck at a given value.
* An IAT sensor 1 low reference circuit that is open can cause the IAT Sensor 1 parameter response to be sluggish.
* The humidity sensor and the IAT sensor 2 signals are sent to the ECM on the same circuit. If the IAT Sensor 2 parameter displays the values: 10 Hz; -40°C (-40°F), and there are Humidity Sensor DTCs, check for a circuit problem.
Reference Information
Schematic Reference
Engine Controls Schematics (LE9) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left (DH6)
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 Signal Generator
For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Tools and Equipment.
Circuit/System Verification
Note: Perform Step 1 of this verification procedure only if the ignition has been OFF for 8 hours or more.
1. Ignition ON, observe the following scan tool parameters. The readings should be within 30°C (54°F) of each other.
* Start-Up IAT Sensor 1
* IAT Sensor 2
* Start-Up ECT
2. Engine running, observe the scan tool IAT Sensor 1 and IAT Sensor 2 parameters. Depending on the current ambient temperature, engine bay conditions, and the vehicle operating conditions, the readings should be between:
* -38 and +149°C (-36 and +300°F) for IAT Sensor 1
* -38 and +149°C (-36 and +300°F) for IAT sensor 2
3. Operate the vehicle within the conditions for running the DTC to verify that 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. Ignition OFF, disconnect the harness connector at the B75C multifunction intake air sensor.
2. Ignition OFF, all systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal 3 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
3. Ignition OFF, all vehicle systems OFF, test for less than 5 ohms 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 the scan tool IAT Sensor 1 parameter is colder than -39°C (-38°F).
• If warmer than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.
Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool IAT Sensor 1 parameter is warmer than 149°C (300°F).
• If colder than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
6. 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.
7. Ignition ON, test for 4.8-5.2 V between the IAT sensor 2 signal circuit terminal 8 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 engine control module.
Note: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
8. Ignition OFF, connect the red lead of the J 38522 - variable signal generator to the signal circuit terminal 8 at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
9. Set the J 38522 - variable signal generator to the following specifications.
* Signal switch to 5 V
* Duty Cycle switch to 50 % (Normal)
* Frequency switch to 30 Hz
10. Ignition ON, observe the scan tool IAT Sensor 2 parameter. The scan tool parameter should be between 28-32 Hz.
• If the parameter is not within the specified range, replace the K20 engine control module.
11. If all circuits test normal, test or replace the B75C multifunction intake air sensor.
Component Testing
1. Ignition OFF, disconnect the harness connector at the B75C multifunction intake air sensor.
Note: A thermometer can be used to test the sensor off the vehicle.
2. Test the IAT sensor 1 by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance - Intake Air Temperature Sensor (Hitatchi Sensor) Temperature Versus Resistance - Intake Air Temperature Sensor (Hitatchi Sensor) table. The resistance values should be in range of the table values.
• If not within the specified range, 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