Diagnostic Test

WARNING: This page is about a different car, the 2015 RAM 3500 HD and 2015 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
1. Start the engine and allow it to reach normal operating temperature.
  WARNING:
  When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
  
  NOTE:
  Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
2. With the scan tool, select View DTCs.
  Is the DTC Active at this time
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (N7) FUEL TANK PRESSURE SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Fuel Tank Assembly in-line harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (N7) Fuel Tank Pressure Sensor Signal circuit at the Fuel Tank Assembly in-line harness connector.
  Is there any voltage reading above 5.2 volts?
  
  Yes
  - Repair the (N7) Fuel Tank Pressure Sensor Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (N7) FUEL TANK PRESSURE SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
  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.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
4. Measure the resistance of the (N7) Fuel Tank Pressure Sensor Signal circuit between the Fuel Tank Assembly in-line harness connector and the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (N7) Fuel Tank Pressure Sensor Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR THE (N7) FUEL TANK PRESSURE SIGNAL CIRCUIT SHORTED TO THE (N8) 5-VOLT SUPPLY CIRCUIT
1. Measure the resistance between the (N7) Fuel Tank Pressure Sensor Signal circuit and the (N8) 5-Volt Supply circuit at the Fuel Tank Assembly in-line harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the short between the (N8) 5-Volt Supply circuit and the (N7) Fuel Tank Pressure Sensor Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (N10) FUEL TANK PRESSURE SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (N10) Fuel Tank Pressure Sensor Ground circuit between the Fuel Tank Assembly in-line harness connector and the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (N10) Fuel Tank Pressure Sensor ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
FUEL TANK PRESSURE SENSOR
1. Turn the ignition off.
2. Reconnect the PCM C2 harness connector.
3. Connect a jumper between the (N7) Fuel Tank Pressure Signal circuit and the (N10) Sensor Ground circuit at the Fuel Tank Assembly in-line harness connector.
4. Turn the ignition on.
5. With the scan tool, monitor the Fuel Tank Pressure Sensor voltage.
  NOTE:
  The sensor voltage should be approximately 0.0 volts (plus or minus .1 volts) with the jumper in place.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Check the Fuel Tank Assembly harness for any signs of damage which could cause an open or shorted circuit. If the harness checks good, replace the Fuel Tank Pressure Sensor in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Tank Pressure Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Fuel Pump Assembly and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL . Refer to PCM/ECM REPROGRAMMING - GAS .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .