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Home >> Jeep >> 2024 >> Grand Cherokee Summit >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 81 (2.0L - DTCS P1C4E To P1E27) >> DTC Troubleshooting >> P1D0D-EVAP System Fuel Tank Pressure Sensor High >> 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, 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 THE (N7) FTP SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Turn the ignition off.
    2. Disconnect the FTP Sensor harness connector.
    3. Turn the ignition on.
    4. Measure the voltage on the (N7) FTP Signal circuit at the FTP Sensor harness connector.

      Is there any voltage reading above 5.2 volts?

      Yes 

      • Repair the (N7) FTP Signal circuit for a short to voltage.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK FOR THE (N7) FTP SIGNAL CIRCUIT SHORTED TO THE (N8) 5-VOLT SUPPLY CIRCUIT 
    1. Turn the ignition off.
    2. Disconnect the PCM C1 harness connector.
    3. Check for continuity between the (N7) FTP Signal circuit and the (N8) 5-Volt Supply circuit at the FTP Sensor harness connector.

      Is there continuity between the (N7) FTP Signal circuit and the (N8) 5-Volt Supply circuit?

      Yes 

      • Repair the short between the (N7) FTP Signal circuit and the (N8) 5-Volt Supply circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE (N7) FTP SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    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. Connect the (special tool #10436, Adapter, GPEC Diagnostic)
      NOTE:

      The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.

    2. Measure the resistance of the (N7) FTP Signal circuit between the FTP Sensor harness connector and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  5

      No 

      • Repair the (N7) FTP Signal circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK THE (N10) FTP SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (N10) Sensor Ground circuit between the FTP Sensor harness connector and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  6

      No 

      • Repair the (N10) Sensor ground circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  6. CHECK THE ABILITY OF THE PCM TO READ THE FTP SENSOR SIGNAL 
    1. Turn the ignition off.
    2. Reconnect the PCM C1 harness connector.
    3. Connect a jumper between the (N7) FTP Signal circuit and the (N10) Sensor Ground circuit at the FTP Sensor harness connector.
    4. Turn the ignition on.
    5. With the scan tool, monitor the FTP Sensor voltage.
      NOTE:

      The P1D0E-EVAP SYSTEM FUEL TANK PRESSURE SENSOR CIRCUIT LOW DTC should be active or pending with the jumper in place.

      Does the scan tool display as described above?

      Yes 

      • Verify that there is good pin to terminal contact in the FTP Sensor and Powertrain Control Module connectors. Replace the FTP Sensor if no problems were found with the connectors.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  7
  7. 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 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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