P2199
DTC P2199
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* 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 is integrated with the mass air flow (MAF) sensor. The IAT sensor is a variable resistor that measures the temperature of the air when it first enters the induction system. This sensor is also used to calculate ambient air temperature. The engine control module (ECM) supplies 5 volts to the IAT sensor signal circuit and supplies a ground to the low reference circuit.
* The intake air temperature (IAT) sensor 2 is integrated with the boost pressure sensor. The IAT sensor 2 is a variable resistor that measures the temperature of the air after the turbocharger and the charge air cooler, and before it enters the engine intake manifold. The engine control module (ECM) supplies 5 volts to the IAT sensor 2 signal circuit and supplies a ground to the low reference circuit.
Conditions for Running the DTC
* The engine is running.
* The MAF is between 9-50 g/s.
* The vehicle speed is greater than 71 km/h (44 mph).
* The boost pressure to barometric (BARO) pressure ratio is less than 1.4.
* The above conditions must be met for greater than 20 seconds.
* This DTC runs continuously within the enabling conditions.
Conditions for Setting the DTC
The ECM detects that the difference in range between the IAT and the IAT sensor 2 either plus or minus is greater than 20°C (36°F) for greater than 4 seconds continuously or 50 seconds cumulative.
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 signal circuit that is shorted to the MAF sensor signal circuit can cause either a rapid fluctuation in the IAT Sensor parameter or cause it to become stuck at a given value.
* An IAT low reference circuit that is open can cause the IAT Sensor parameter response to be sluggish.
* An IAT sensor 2 signal circuit that is shorted to the boost pressure sensor signal circuit may cause the IAT Sensor 2 parameter response to be sluggish or become stuck at a given value.
Circuit/System Verification
Important: Determine the ambient temperature by using an accurate thermometer.
* If the ignition has been OFF for 8 hours or greater, the IAT, the IAT 2 and the engine coolant temperature (ECT) should be within 9°C (16°F) of each other and also the ambient temperature. Ignition ON, observe the scan tool IAT Sensor, IAT 2 Sensor and the ECT Sensor parameters. Compare those sensor parameters to each other and also to the ambient temperature to determine if the condition is current.
* Engine running, observe the scan tool IAT Sensor parameter. The reading should be between -39 to +120°C (-38 to +248°F) depending on the current ambient temperature and the vehicle operating conditions.
* Engine running, observe the scan tool IAT Sensor 2 parameter. The reading should be between -39 to +140°C (-38 to +284°F) depending on the current ambient temperature and the vehicle operating conditions.
Circuit/System Testing
1. Ignition OFF, disconnect the MAF/IAT harness connector at the MAF/IAT sensor.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the MAF sensor ground circuit and ground.
• If greater than the specified range, test the MAF sensor ground circuit for an open/high resistance.
3. Ignition OFF, test for less than 5 ohms of resistance between the IAT low reference circuit 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 ECM.
4. Ignition OFF, disconnect the IAT sensor 2 harness connector at the boost pressure sensor.
5. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit 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 ECM.
6. Ignition OFF, disconnect the ECM.
7. Ignition OFF, test for less than 5 ohms of resistance on the IAT sensor signal circuit.
• If greater than the specified range, test the IAT sensor signal circuit for an open/high resistance.
8. Ignition OFF, test for less than 5 ohms of resistance on the IAT sensor 2 signal circuit.
• If greater than the specified range, test the IAT sensor 2 signal circuit for an open/high resistance.
9. If the circuits test normal, test both the IAT sensor and the IAT sensor 2.
Component Testing
Measure and record the resistance of the IAT sensor and the IAT sensor 2 at various ambient temperatures, then compare those measurements to the Temperature vs Resistance table. Refer to Temperature Versus Resistance.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Mass Airflow Sensor Replacement
* Intake Air Pressure and Temperature Sensor Replacement
* Refer to Programming and Relearning for ECM setup and programming. Programming and Relearning