Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FUSE F73
NOTE:
During cold climate, gelled fuel in Auxiliary Fuel Tank MAY cause this DTC to set.
1. With the scan tool, read PCM DTCs and record on the repair order.
2. With the scan tool, record all Freeze frame Data.
3. Check Fuse F73 (20A) for an open.
  Was Fuse F73 (20A) open?
  
  Yes
  - Replace Fuse F73 (20A) and determine the source of the short circuit that caused the Fuse to blow.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 2
CHECK THE (N9) FUEL PUMP 2 CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
  NOTE:
  Check connectors - Clean/repair as necessary.
3. Turn the ignition on.
4. Measure for voltage on the (N9) Fuel Pump 2 Control circuit at the PCM C2 harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (N9) Fuel Pump 2 Control circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (N69) FUEL PUMP 2 ON/OFF CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the BCM C1 harness connector.
3. Disconnect the Power Distribution Center (PDC) C6 harness connector.
  NOTE:
  Check connectors - Clean/repair as necessary.
4. Check for continuity between ground and the (N69) Fuel Pump 2 On/Off Control circuit at the BCM C1 harness connector.
  Is there continuity between ground and the (N69) Fuel Pump 2 On/Off Control circuit?
  
  Yes
  - Repair the (N69) Fuel Pump 2 On/Off Control circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (N69) FUEL PUMP 2 ON/OFF CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (N69) Fuel Pump 2 On/Off Control circuit between the BCM C1 harness connector and the PDC C6 harness connector.
  Is resistance above 3.0 Ohms?
  
  Yes
  - Repair the (N69) Fuel Pump 2 On/Off Control circuit for an open/high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (N2) AUXILIARY FUEL PUMP SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Disconnect the Auxiliary Fuel Pump Module harness connector.
2. Measure the resistance of the (N2) Auxiliary Fuel Pump Supply circuit between the Auxiliary Fuel Pump Module harness connector and the PDC C6 harness connector.
  Is resistance above 3.0 Ohms?
  
  Yes
  - Repair the (N2) Auxiliary Fuel Pump Supply circuit for an open/high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK THE FUEL TRANSFER LINE TUBE
1. Inspect the Fuel Transfer Line Tube from the Auxiliary Fuel Tank to the Primary Fuel Tank for binding, kinking, obstruction, or other damage.
  Was there any damage or obstruction found at the tube?
  
  Yes
  - Repair or replace the Fuel Transfer Line Tube in accordance with the Service Information. Reconnect all hoses and connectors. Retest using the When Monitored, Set Conditions, and Freeze frame Data to verify that the DTC no longer sets.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
INTERNAL INSPECTION OF THE AUXILIARY FUEL TANK
WARNING:
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
1. Remove the Auxiliary Fuel Tank in accordance with the Service Information.
2. Remove the Auxiliary Fuel Pump Module.
3. Visually inspect the inside of the Auxiliary Fuel Tank for any gelled fuel, obstructions, deformities, or other damage.
4. Visually inspect the Auxiliary Fuel Pump Module Float arm for damage.
  Were any problems found?
  
  Yes
  - Repair or replace as necessary. Reconnect all hoses and connectors. Retest using the When Monitored, Set Conditions, and Freeze frame Data to verify that the DTC no longer sets.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
AUXILIARY FUEL PUMP MODULE
1. Replace the Auxiliary Fuel Pump Module in accordance with the Service Information.
2. Reconnect all hoses and connectors. Retest using the When Monitored, Set Conditions, and Freeze frame Data to verify that the DTC no longer sets.
  Did the DTC return?
  
  Yes
  - Go To 9
  No
  - Test Complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE PCM/PDC
1. Turn the Ignition off.
2. Disconnect the PDC C3 harness connector.
3. Reconnect the PCM C2 harness connector.
4. Turn the ignition on, engine off.
5. Using a 12-Volt test light connected to 12 Volts, probe the (N9) Fuel Pump 2 Control circuit at the PDC C3 harness connector.
6. With the scan tool, toggle the Auxiliary Pump actuator.
  NOTE:
  The test light must illuminate as brightly as a direct connection to the Battery.
7. Observe the test light while toggling the Auxiliary Pump actuator.
  Does the test light cycle on and off and illuminate brightly?
  
  Yes
  - Replace the Power Distribution Center (PDC) in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, (PCM) DIESEL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .