GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Optra - Mexico 🢒 DTC 🢒 DTC P2279

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 P2279: Intake Manifold Air Leak

Circuit/System Description

The engine control module (ECM) compares actual vacuum reading of the manifold absolute pressure (MAP) sensor at idle to a calculated vacuum reading.

Conditions for Running the DTC
    • DTCs P0106, P0107, P0108, P0112, P0113, P0115, P0117, P0118, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0141, P0171, P0172, P0201-P0204, P0217, P0300, P0336, P0337, P0341, P0342, P0351, P0352, P0402, P0404, P0405, P0406, P0488, P0496, P0502, P2195, and P2196 are not set.
    • The evaporative emission (EVAP) purge canister commanded state is less than 100 percent.
    • The barometric pressure (BARO) is greater than 72 kPa.
    • The engine coolant temperature (ECT) is greater than 60°C (140°F).
    • The intake air temperature (IAT) sensor is greater than -20°C (-4°F).
    • The manifold absolute pressure (MAP) is less than 60 kPa.
    • The engine is operating for more than 60 seconds.
    • The engine is at idle with the throttle closed.
    • The ECM is not commanding an IAC motor reset.
    • The following components are not changing states:
       - The A/C compressor
       - The engine cooling fans
       - The automatic transmission
    • The DTC runs continuously when the above conditions are met for 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

DTC P2279 is a Type B DTC.

Conditions for Clearing the DTC

DTC P2279 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Description and Operation

Air Intake System Description

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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification
  1. 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. DTC P2279 should not set.
  2. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

Circuit/System Testing
  1. Verify that none of the following conditions exist:
    2. • The air intake duct system for loose connecting clamps, cracks, or other damage
    • A damaged throttle body blade or shaft
    • Splits, kinks, or improper connections at the vacuum hoses
    • An exhaust gas recirculation (EGR) system leak
    • Faulty positive crankcase ventilation (PCV) system operation
    • Carbon deposits on the throttle blade--Refer to Throttle Body Inspection and Cleaning .
    • Vacuum leaks at the intake manifold, throttle body, and injector O-rings
  2. If all conditions test normal, test the engine for proper camshaft timing. Refer to Timing Belt Replacement .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Throttle Body Assembly Replacement
    •  Air Cleaner Assembly Replacement