LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 2018 >> Grand Cherokee Laredo, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 6 (3.0L Diesel - DTCS P01CD-00 To P0402-00) >> DTC Troubleshooting >> P0402-00-EGR Flow Excessive Detected >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different variant/trim than selected.
  1. CHECK FOR AN ACTIVE DTC 
    1. Turn the ignition on.
    2. With the scan tool, read and record DTCs and Freeze Frame data on the repair order.
    3. With the scan tool, erase PCM DTCs.
    4. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    5. With the scan tool, read DTCs and record on the repair order.

      Is the DTC active or pending?

      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 Mass Air Flow Sensor DTCs active or pending?

      Yes 

      No 

      • Go To  3
  3. VISUALLY INSPECT THE AIR FILTER FOR EXCESSIVE DIRT OR DEBRIS 
    1. Turn the ignition off.
    2. Remove and inspect the Air Filter for soiling or excessive dirt and debris which may cause air flow restriction.

      Were any of these problems found?

      Yes 

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

      No 

      • Go To  4
  4. CHECK THE AIR INTAKE AND EXHAUST SYSTEMS FOR A RESTRICTION 
    1. Visually inspect the fresh air inlet tube for a blockage due to snow, ice or dirt buildup.
    2. Visually inspect the intake system, exhaust system and related tubes and connections.
      NOTE:

      Inspect all air intake, crankcase vent and Turbocharger related tubes for damage, restriction or poor connection. Any of these conditions can cause this DTC to set.

      NOTE:

      Inspect the exhaust system and related tubes for damage, restriction or poor connection. Any of these conditions can cause this DTC to set.

      Were any problems found?

      Yes 

      • Repair as necessary in accordance with the Service Information.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK THE INTAKE AIR SYSTEM FOR LEAKS 
    1. Perform the Engine Diagnosis and Testing INTAKE AIR SYSTEM LEAK DETECTION test procedure. Refer to INTAKE AIR SYSTEM LEAK DETECTION .

      `

      Is there evidence of a leak?

      Yes 

      • Repair as necessary in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Go To  6
  6. CHECK THE EGR AIR FLOW CONTROL VALVE FOR PROPER OPERATION 
    1. Disconnect the air tube at the inlet port of the EGR Air Flow Control Valve.
    2. Use a mirror to observe the motion of the EGR Air Flow Control Valve.
    3. Turn the ignition on.
    4. The EGR Air Flow Control Valve should open completely without binding with the ignition on.
      NOTE:

      Cycle the ignition on and off several times while observing the operation of the valve.

      Did the EGR Air Flow Control Valve operate correctly and without binding?

      Yes 

      • Go To  7

      No 

  7. CHECK THE EGR COOLER AND TUBES FOR LEAKS OR RESTRICTIONS 
    1. Turn the ignition off.
    2. Gain access to and inspect the EGR Cooler and both tubes that connect to the EGR Cooler. Check tubes and cooler for damage, leaks, excessive soot build up and other problems that could restrict or prevent proper exhaust gas flow.
      NOTE:

      Compressed air (at low pressure) can be applied to the lower port of the EGR Cooler. When applying compressed air check for air to flow through cooler and out the upper port. Always wear safety glasses when working with compressed air.

      Were any problems found?

      Yes 

      No 

scientia non olet · About LEMON Manuals