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Home >> Jeep >> 2018 >> Grand Cherokee Laredo, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 9 (3.0L Diesel - DTCS P1693-00 To P2200-00) >> DTC Troubleshooting >> P20FC-00-REDUCTANT Pump 2 Control Circuit Low >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different variant/trim than selected.
  1. DTC IS ACTIVE 
    1. Ignition on, engine not running.
    2. With the scan tool, erase DTCs in the PCM.
    3. Start the engine and allow the engine to reach normal operating temperature.
    4. Monitor the scan tool for at least two minutes.
    5. With the scan tool, select View DTCs.

      Is the status Active for this DTC?

      Yes 

      • Go To  2

      No 

      • Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .
  2. CHECK THE (K481) DEF PURGE PUMP CONTROL CIRCUIT FOR A SHORT TO GROUND 
    1. Turn the ignition off.
    2. Disconnect the DEF Pump C1 harness connector.
    3. Disconnect the PCM C1 harness connector.
    4. Measure the resistance between ground and the (K481) DEF Purge Pump Control circuit at the DEF Pump C1 harness connector.

      Is the resistance above 10k Ohms?

      Yes 

      • Go To  3

      No 

      • Repair the (K481) DEF Purge Pump Control circuit for a short to ground.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  3. DEF PUMP-LEVEL/TEMP SENSOR 
    1. Replace the DEF Pump in accordance with the service information.
    2. Reconnect the DEF Pump C1 harness connector.
    3. Reconnect the PCM C1 harness connector.
    4. Ignition on, engine not running.
    5. With the scan tool, erase DTCs in the PCM.
    6. Start the engine.
    7. Allow the engine to reach normal operating temperature.
    8. Monitor the scan tool for at least two minutes.
    9. With the scan tool, select View DTCs.

      Is the status Active for this DTC?

      Yes 

      • Go To  4

      No 

  4. POWERTRAIN CONTROL MODULE 
    1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the DEF Pump and the Powertrain Control Module.
    2. Look for any chafed, pierced, pinched, or partially broken wires.
    3. Look for broken, bent, pushed out or corroded terminals.
    4. Perform any Technical Service Bulletins that may apply.

      Were any problems found?

      Yes 

      No 

      • Replace the Powertrain Control Module in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .