LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 2021 >> Grand Cherokee L Laredo, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (5.7L - DTCS P0456 To P0629) >> DTC Troubleshooting >> P0506-Idle Speed Performance Lower Than Expected >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different variant/trim than selected.
  1. READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN 
    1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
    2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
    3. With the scan tool, erase all DTCs.
    4. Turn the ignition off for a minimum of 10.0 seconds.
    5. Turn the ignition on.
    6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
    7. With the scan tool, read DTCs.

    Did the DTC return?

    Yes 

    • Go To  2

    No 

  2. CHECK FOR OTHER DTCS 
    1. Refer to the recorded DTCs.

      Are there any Throttle Body DTCs active or pending?

      Yes 

      No 

      • Go To  3
  3. INSPECT THE AIR INDUCTION SYSTEM FOR RESTRICTIONS 
    1. Turn the ignition off.
    2. Inspect the Air Induction System for restrictions - Dirty Air Cleaner, Foreign material trapped in the air intake tube, etc.

      Were any problems found?

      Yes 

      No 

      • Go To  4
  4. INSPECT THE PCV SYSTEM HOSES AND TUBES FOR RESTRICTIONS 
    1. Inspect the PCV system for restrictions - sticking valve, collapsed hoses or tubes, obstructed passages or ports, etc.

      Were any problems found?

      Yes 

      No 

      • Go To  5
  5. CHECK THE THROTTLE BODY FOR PROPER OPERATION 
    1. Inspect the Throttle Body for carbon build up, other restrictions, and a bent throttle plate using a straight edge.
    2. If the throttle plate does not close entirely it may be bent and needs to be replaced.
      WARNING:

      When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.

    3. Start the engine.
    4. While the vehicle is running, lightly tap on ETC Motor where applicable, with your hand, and listen for idle to raise.

      Were any problems found or did the idle fluctuate while tapping on the ETC Motor?

      Yes 

      • Verify that there is good pin to terminal contact at the Throttle Body and the Powertrain Control Module connectors. Repair or replace the Throttle Body Assembly if no problems were found in the connectors. Disconnect the Battery when replacing the Throttle Body Assembly. Refer to THROTTLE BODY, REMOVAL AND INSTALLATION . After installation is complete, use a scan tool and select the ETC RELEARN function.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
  6. CHECK RELATED PCM AND COMPONENT CONNECTIONS 
    1. Perform any Service Bulletins that apply.
    2. Disconnect all PCM harness connectors.
    3. Disconnect all related in-line harness connections (if equipped).
    4. Disconnect the related component harness connectors.
    5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    9. With the scan tool, erase DTCs.
    10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    11. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No