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For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 Wave 🢒 Engine 🢒 Engine Controls - 1.6L (L91) 🢒 DTC P2279

Description

The engine control module (ECM) monitors the volume of air consumed at idle speed. The ECM controls the idle air control (IAC) motor in order to regulate the air flow through the throttle body. The amount of air flowing through the throttle body will normally determine the engine speed. If there is an intake air leak or a malfunction in the positive crankcase ventilation (PCV) system excess air can enter the intake manifold affecting engine speed. The ECM uses sensor input in order to determine an estimated volume of air that is used during normal idle conditions. If there is any excess air, the estimated volume of air will be more than the expected value and DTC P2279 sets.

DTC Descriptor

This diagnostic supports the following DTC:

DTC P2279 Intake Air (IA) Duct Air Leak

Conditions for Running the DTC
    •  DTCs P0106, P0107, P0108, P0112, P0113, P0115, P0117, P0118, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0141, P0171, P0172, P0201-P0204, P0217, P0300, P0336, P0337, P0341, P0342, P0351, P0352, P0402, P0404, P0405, P0406, P0441, P0488, P0502, P2195, and P2196 are not set.
    • The ignition 1 voltage is between 11-16 volts.
    • The intake air temperature (IAT) is more than -20°C (-4°F).
    • The engine coolant temperature (ECT) is more than 60°C (140°F).
    • The engine is operating for more than 60 seconds.
    • The barometric pressure (BARO) is more than 72 kPa.
    • The manifold absolute pressure (MAP) is less than 60 kPa.
    • The engine is at idle with the throttle closed.
    • The following components are not changing states:
       - The A/C compressor
       - The engine cooling fans
       - The automatic transmission
    • The ECM is not commanding an idle air control (IAC) motor reset.
    • DTC P2279 runs continuously once the above conditions are met for more than 5 seconds.

Conditions for Setting the DTC
    • The ECM detects that the predicted intake air flow into the engine is not within a predetermined range of the actual air flow into the engine.
    • The condition exists for more than 20 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers in the diagnostic table.

  1. This step prompts the technician to check for any condition that can allow air to enter the engine. Any condition that can affect the idle speed of the engine must be repaired first, in order to enable the correct diagnosis of the DTC P2279.

    2.

  2. Deposits on the throttle valve can affect the air flow through the throttle body and into the engine.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Turn ON the ignition, with the engine OFF.
  2. Clear the diagnostic trouble code (DTC) with a scan tool.
  3. Start the engine.
  4. Observe the DTC Info with a scan tool.

Did the DTC fail this ignition?

Go to Step 3

Go to Step 4

3

Did DTC P0506 or P0507 also set?

Go to DTC P0506 or P0507

Go to Step 5

4

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 5

Go to Intermittent Conditions

5
  1. Inspect the engine for any of the following conditions:
    2. • A stuck or damaged throttle valve or throttle body
    • A vacuum or intake air leak
    • An evaporative emission (EVAP) system malfunction
    • An EGR system leak
    • Faulty PCV system operation
  2. Repair the condition as necessary.

Did you find and correct a condition?

Go to Step 8

Go to Step 6

6

Inspect the throttle valve for excessive deposits. Clean as necessary. Refer to Throttle Body Inspection and Cleaning .

Did you find and correct a condition?

Go to Step 8

Go to Step 7

7
  1. Inspect the camshaft timing. Refer to Timing Belt Replacement in Engine Mechanical - 1.6L (L91).
  2. Repair the condition as necessary.

Did you find and correct a condition?

Go to Step 8

Go to Intermittent Conditions

8
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 9

9

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK