GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • 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 Sensor 1-2 Correlation

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

IAT Sensor 1 Signal

P0112

P0113

P0113

P0113

IAT Sensor 1 Low Reference

--

P0113

P0113

--

IAT Sensor 2 Signal

P0097

P0098

P0098

P0098

IAT Sensor 2 Low Reference

--

P0098

P0098

--

Circuit/System Description

The intake air temperature (IAT) sensor 1 is fitted between the air cleaner and turbocharger. It is internal to the mass air flow (MAF) sensor and measures the temperature of the air entering the engine. The IAT sensor 2 is installed to the intake manifold, and measures the temperature of the air entering the engine that mixed with exhaust gas recirculation (EGR) gas. The engine control module (ECM) monitors difference of temperature from both sensor inputs continuously. If the ECM detects that difference of temperature between both inputs are more than a calculated value, this DTC will set.

Conditions for Running the DTC

    • DTCs P0097, P0098, P0112, P0113, P0117, P0118, P0126, P0237, P0238, P0409, P042E, P0642, P0643, P0652 and P0653 are not set.
        AND
    • The following conditions are met for longer than 5 minutes:
       - The battery voltage is between 10-16 volts.
       - The ignition switch is ON.
       - The EGR valve position is 0 percent.
       - The engine run time is between 30-600 seconds.
       - The engine coolant is between -7 to +55°C (+19 to +131°F).
       - The boost pressure is less than 7.2 psi (50 kPa).

Conditions for Setting the DTC

The ECM detects that the intake air temperature 2 is more than 50°C (122°F) over the intake air temperature 1.

Action Taken When the DTC Sets

DTC P2199 is a Type B DTC.

Conditions for Clearing the DTC

DTC P2199 is a Type B DTC.

Diagnostic Aids

    • Before starting a cold engine, the intake air temperature 1 and 2 should be relatively close to each other.
    • If an intermittent condition is suspected, refer to Testing for Intermittent Conditions and Poor Connections.
    • Use the Temperature vs. Resistance Temperature Versus Resistance table to test the IAT sensor 1 or 2 at various temperature levels to evaluate the possibility of a skewed sensor.
    • A sticking or intermittently sticking EGR valve may set this DTC.
    • Skewed engine coolant temperature sensor or skewed boost pressure sensor may set this DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify the integrity of the Glow plug relay control circuit by inspecting for the following conditions:

    • Damaged components
    • Loose or improper installation

Circuit/System Testing

Important: You must perform Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition OFF, disconnect the harness connectors at IAT sensor 1 or the IAT sensor 2.
  2. Ignition OFF, test for 4.8 volts between the applicable IAT sensor signal circuit and ground.
  3. If less than 4.8 volts, test the applicable signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Install a 3A fused jumper wire between the applicable signal circuit and the applicable low reference circuit for IAT sensor. Verify that the DMM is greater than 4.8 volts.
  5. If less than 4.8 volts, test the applicable low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  6. If all circuits test normal, test or replace the affected sensor.

Component Testing

Test the IAT sensor 1 and 2 at various temperature levels to evaluate the possibility of a skewed sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Mass Airflow Sensor/Intake Air Temperature Sensor Replacement
    •  Control Module References for ECM replacement, setup, and programming