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Home >> Jeep >> 2023 >> Grand Cherokee Altitude, AWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 50 (2.0L - DTCS P1E28 To P2123) >> DTC Troubleshooting >> P1E80 Cylinder 4 Injector Short >> 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. ISOLATE AND CHECK THE FUEL INJECTOR 4 (K14) HIGH SIDE CONTROL CIRCUIT FOR A SHORT TO THE FUEL INJECTOR 4 (K614) LOW SIDE CONTROL CIRCUIT 
    1. The ignition must be off when checking for a short between circuits.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the appropriate SYSTEM WIRING DIAGRAM as a guide to follow the path of the circuit.
    3. Connect the test leads of the DVOM and check for continuity between the circuits being tested at the component harness connector.
    CAUTION:

    Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.

    1. If it is necessary to probe a terminal at a PCM harness connector, connect the special tool # 10436, (GPEC Diagnostic Adapter) to the appropriate PCM harness connector.
      NOTE:

      There should be no continuity between the circuits being tested.

      Is there continuity between the circuits?

      Yes 

      No 

      • Go To  3
  3. CHECK THE FUEL INJECTOR 4 RESISTANCE 
    1. Measure the resistance between the terminals of Fuel Injector 4.
      NOTE:

      Low resistance in the Fuel Injector can mimic the control circuits being shorted together causing this DTC to set.

      NOTE:

      The resistance of the Fuel Injectors should be approximately 1.9 Ohms. It may be best to compare the resistance of the suspect injector to the other known good injectors on the vehicle.

      Is the resistance of Fuel Injector 4 within 10% of the other known good injectors?

      Yes 

      • Go To  4

      No 

  4. 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