LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2021 >> Grand Cherokee Trackhawk >> Repair and Diagnosis >> Engine Performance >> System >> 6.2L - DTCS P0850 To P2107 >> DTC Troubleshooting >> P120B-Fuel Pump Control Module "B" Open Circuit To Fuel Pump >> Diagnostic Test
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. Turn the ignition on, engine not running.
    2. With the scan tool, read DTCs.

      Is the DTC active?

      Yes 

      • Go To  2

      No 

  2. CHECK THE (N213) FUEL PUMP PWM CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the FPCM 2 harness connector.
    3. Disconnect the Fuel Pump Module harness connector.
    4. Measure the resistance of the (N213) Fuel Pump PWM Control circuit between the FPCM 2 harness connector and the Fuel Pump assembly harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  3

      No 

      • Repair the (N213) Fuel Pump PWM Control circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  3. CHECK THE (N214) FUEL PUMP PWM RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (N214) Fuel Pump PWM Return circuit between the FPCM 2 harness connector and the Fuel Pump assembly harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      No 

      • Repair the (N214) Fuel Pump PWM Return circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .