LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 2018 >> Grand Cherokee Laredo, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 8 (3.0L Diesel - DTCS P0627-00 To P1692-00) >> DTC Troubleshooting >> P1220-00-Excessive Cycling Of REDUCTANT Line Air Purging Control >> Diagnostic Test

Diagnostic Test

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

      Is the status Active for this DTC?

      Yes 

      • Go To  2

      No 

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

      Are there any DEF Supply Pump DTCs active or pending?

      Yes 

      No 

      • Go To  3
  3. CHECK THE DEF SUPPLY SYSTEM FOR LEAKS 
    1. Using the scan tool, begin the DEF Injector Quantity Test
    2. During the DEF Injector Quantity Test, visually inspect the DEF Supply Pump Assembly and DEF Pressure Line for signs of a fluid leak.

      Are there any leaks in the DEF System?

      Yes 

      • Perform the appropriate repair. If P241D was also present, it will be necessary to reset the SCR Timer: Using the scan tool, Go to Misc. Functions> SCR Extend Mileage W Active Fault (and reset the Timer).
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE (K481) DEF PURGE PUMP CONTROL CIRCUIT FOR SHORT TO VOLTAGE 
    1. Turn the ignition off.
    2. Disconnect the DEF Pump_Temp/Level Sensor C1 harness connector.
    3. Turn the ignition on.
    4. Measure the voltage on the (K481) DEF Purge Pump Control circuit at the DEF Pump_Temp/Level Sensor C1 harness connector.

      Is there voltage above 5.2 volts present?

      Yes 

      • Repair the (K481) DEF Purge Pump Control circuit for a short to voltage. Reset the SCR Timer: Using the scan tool, Go to Misc. Functions> SCR Extend Mileage W Active Fault (and reset the Timer). Also, test drive the vehicle for 30 miles before beginning the PCM VERIFICATION Test.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK THE (K481) DEF PURGE CONTROL CIRCUIT FOR SHORT TO GROUND 
    1. Turn the ignition off.
    2. Disconnect the PCM C2 harness connector.
    3. Measure the resistance between ground and the (K481) DEF Purge Pump Control circuit at the DEF Pump_Temp/Level Sensor C1 harness connector.

      Is the resistance above 10k Ohms?

      Yes 

      • Go To  6

      No 

      • Repair the (K481) DEF Purge Pump Control circuit for a short to ground. Reset the SCR Timer: Using the scan tool, Go to Misc. Functions> SCR Extend Mileage W Active Fault (and reset the Timer). Also, test drive the vehicle for 30 miles before beginning the PCM VERIFICATION Test.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  6. CHECK THE (K401) SCR RELAY 1 CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (K481) DEF Purge Control circuit between the DEF Pump_Temp/Level Sensor C1 harness connector and the PCM C2. harness connector.

      Is the resistance above 5.0 Ohms?

      Yes 

      • Repair the (K481) DEF Purge Control circuit for an open/high resistance. Reset the SCR Timer: Using the scan tool, Go to Misc. Functions> SCR Extend Mileage W Active Fault (and reset the Timer). Also, test drive the vehicle for 30 miles before beginning the PCM VERIFICATION Test.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Go To  7
  7. CHECK THE DEF PUMP FOR PROPER OPERATION 
    1. Replace the DEF Pump in accordance with the service information.
    2. Reconnect the PCM C2 harness connector.
    3. Reconnect the DEF Pump_Temp/Level Sensor C1 harness connector.
    4. Turn the ignition on.
    5. With the scan tool, erase PCM DTCs.
    6. Start the engine and run it until it reaches operating temperature.
    7. Test drive the vehicle under normal operating conditions.
    8. With the scan tool, read PCM DTCs.

      Does the scan tool display this DTC?

      Yes 

      • Go To  8

      No 

      • Test complete. Reset the SCR Timer: Using the scan tool, Go to Misc. Functions> SCR Extend Mileage W Active Fault (and reset the Timer). Also, test drive the vehicle for 30 miles before beginning the PCM VERIFICATION Test.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  8. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all PCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. 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.

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

      Did the DTC return?

      Yes 

      • Replace the Powertrain Control Module in accordance with the service information. Reset the SCR Timer: Using the scan tool, Go to Misc. Functions> SCR Extend Mileage W Active Fault (and reset the Timer). Also, test drive the vehicle for 30 miles before beginning the PCM VERIFICATION Test. Refer to PCM VERIFICATION TESTMODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Repair the poor connections.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
scientia non olet · About LEMON Manuals