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Home >> Jeep >> 2018 >> Grand Cherokee Laredo, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 10 (3.0L Diesel - DTCS P2201-00 To P24F2-00) >> DTC Troubleshooting >> P2279-00-Intake Air System Leak >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different variant/trim than selected.
  1. CHECK FOR AN ACTIVE DTC 
    1. Ignition on, engine not running.
    2. With the scan tool, erase DTCs in the PCM.
    3. Start the engine and allow it to reach normal operating temperature.
    4. With the scan tool, select View DTCs.

      Is the status Active for this DTC?

      Yes 

      • Go To  2

      No 

      • Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .
  2. CHECK FOR OTHER DTCS 
    1. Refer to the recorded DTCs.

      Are there any 5-Volt Reference, MAF Sensor, Intake Air System, Turbocharger or EGR System DTCs active or pending?

      Yes 

      No 

      • Go To  3
  3. CHECK THE AIR FILTER FOR TEARING OR IMPROPER INSTALLATION 
    1. Turn the ignition off.
    2. Remove and inspect the Air Filter for tearing or being mis-installed which may cause excessive air flow.

      Were any of these problems found?

      Yes 

      • Replace the Air Filter in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM 
    1. Remove the Inlet Pressure Sensor.
    2. Connect smoke machine 84-04 to the Inlet Pressure Sensor port in the intake duct and begin injecting smoke into the intake system.
    3. Observe all intake system components for evidence of smoke leakage.

      Is there evidence of smoke leakage?

      Yes 

      No 

      • Go To  5
  5. CHECK THE EGR VALVE FOR PROPER OPERATION 
    NOTE:

    An EGR Valve that is stuck partially open can cause this DTC to set. Hard starting, rough running and black smoke from the tailpipe are signs of an EGR Valve that is stuck open. 

    1. While starting and test driving the vehicle, observe for the conditions mentioned in the note above.

      Does the vehicle exhibit these conditions?

      Yes 

      • Replace the EGR Valve in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Replace the Mass Air Flow Sensor in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .