Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P2279: Intake Air System Leak
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
- If DTC P0443 is stored at the same time as DTC P2279, troubleshoot DTC P0443 first, then recheck for DTC P2279.
- Check for vacuum leaks at these parts:
- PCV valve
- PCV hose
- Purge (PCS) line
- Throttle body
- Intake manifold
- Brake booster
- Brake booster hose
Are the parts OK?
YES -Go to step 2.
NO -Repair or replace any damaged part(s), then Go to step 4.
- Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle 1 minute.
- Monitor the OBD STATUS for DTC P2279 in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
YES -Check the camshaft timing (see CAM CHAIN INSTALLATION ), then Go to step 4.
NO -If the screen indicates PASSED, intermittent failure, the system is OK at this time. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, Go to step 2 and recheck.
- Reset the PCM with the HDS.
- Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC P2279 indicated?
YES -Check for vacuum leaks at the PCV valve, the PCV hose, the purge (PCS) line, the throttle body, the intake manifold, the brake booster, and the brake booster hose, then Go to step 1.
NO -Go to step 7.
- Monitor the OBD STATUS for DTC P2279 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 6, go to the indicated DTC's troubleshooting.
NO -If the screen indicates FAILED, Go to step 1. If the screen indicates EXECUTING or OUT OF CONDITION, keep idling until a result comes on.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.