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 sensors listed below are integrated within the mass air flow/multifunction intake air sensor:
* IAT sensor 1
* IAT sensor 2
* Humidity sensor
* MAF sensor
* BARO pressure sensor
The intake air temperature (IAT) sensor 1 is a variable resistor that changes the voltage on the engine control module (ECM) supplied 5 V signal circuit. The signal varies with inlet air temperature in the sensor bore and is displayed by the scan tool as °C (°F). The IAT sensor 2 and the humidity sensor share the same circuit. The IAT sensor 2 signal is displayed by the scan tool as Hertz (Hz) and °C (°F).
The sensors listed below share an ECM supplied 5 V reference circuit:
* IAT sensor 2
* Humidity sensor
* Barometric pressure (BARO) sensor
The sensors listed below share an ECM supplied low reference circuit:
* IAT sensor 1
* IAT sensor 2
* Humidity sensor
* Barometric pressure (BARO) sensor
Conditions for Running the DTC
* DTC P1682 is not set.
* The ignition is ON.
* Ignition voltage is at least 11 V.
* 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
* 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 scan tool IAT Sensor 2 parameter displays the values: 10 Hz; 20°C (68°F) when there is a fault on the signal circuit.
* 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; 20°C (68°F), and there are also Humidity Sensor DTCs, check for a circuit problem.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
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
EN 38522 - Variable Signal Generator
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
Note: To minimize the effects of the sensor heating elements, 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 25°C (45°F) of each other.
* Start-Up IAT Sensor 1
* IAT Sensor 2
* Start-Up ECT
2. Engine idling, observe the scan tool IAT Sensor 1 and IAT Sensor 2 Sensor parameters. Depending on the current ambient temperature and the vehicle operating conditions, the readings should be between -39 and +149°C (-38 and +300°F).
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 7 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 ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground.
• If less than the specified range, test the circuit for an open/high resistance, or short to ground on the 5 V reference circuit. If the circuit tests normal, replace the K20 Engine Control Module.
• If greater than the specified range, test for a short to voltage on the 5 V reference circuit. If the circuit tests normal, replace the K20 Engine Control Module.
4. 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 terminal 8 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
5. Test for 4.8-5.2 V between the IAT sensor 1 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 ECM 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.
6. Test for 4.8-5.2 V between the IAT sensor 2 signal circuit terminal 1 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 ECM 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.
7. Ignition OFF. Connect the leads of the EN 38522 - Variable Signal Generator as follows:
* Red lead to the signal circuit terminal 1 at the harness connector
* Black lead to ground
* Battery voltage supply lead to B+
8. Set the EN 38522 - Variable Signal Generator to the following specifications.
* Signal switch to 5 V
* Duty Cycle switch to 50 % (Normal)
* Frequency switch to 30 Hz
9. Ignition ON. Observe the scan tool IAT Sensor 2 frequency (Hz) parameter. The scan tool parameter should display between 28-32 Hz.
• If the parameter is not within the specified range, replace the K20 Engine Control Module.
10. 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 (Bosch Sensor) Temperature Versus Resistance - Intake Air Temperature Sensor (Bosch Sensor)Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) Temperature Versus Resistance - Intake Air Temperature Sensor (Delco Sensor) Bosch 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 Replacement Service and Repair for Mass Air Flow/Multifunction Intake Air Sensor replacement.
* Control Module References Control Module References for Engine Control Module replacement, programming, and setup.