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
- Turn the ignition on.
- With the scan tool, read DTCs.NOTE:
Diagnose and repair any system voltage or 5-Volt Sensor Reference DTCs before continuing with this test.
Does the scan tool display this DTC as active?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK THE (N8) 5-VOLT SUPPLY CIRCUIT VOLTAGE
- Turn the ignition off.
- Disconnect the Fuel Tank Assembly in-line harness connector.
- Turn the ignition on.
- Measure the voltage on the (N8) 5-Volt Supply circuit at the Fuel Pump Assembly harness connector.
Is the voltage between 4.8 and 5.2 volts?
Yes
- Go To 3
No
- Repair the (N8) 5-Volt Supply circuit for an open or short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE FUEL TANK PRESSURE SENSOR
- With the scan tool, view the Fuel Tank Pressure Sensor voltage with the Fuel Tank Assembly in-line harness connector disconnected.NOTE:
The sensor voltage should be approximately 5.0 volts (plus or minus .1 volts) with the connector disconnected.
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 4
- With the scan tool, view the Fuel Tank Pressure Sensor voltage with the Fuel Tank Assembly in-line harness connector disconnected.
- CHECK THE (N7) FUEL TANK PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Turn the ignition off.
- Disconnect the PCM C1 harness connector.
- Measure the resistance between ground and the (N7) Fuel Tank Pressure Sensor Signal circuit at the Fuel Tank Assembly harness connector.
Is the resistance above 10k Ohms?
Yes
- Go To 5
No
- Repair the (N7) Fuel Tank Pressure Sensor Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK FOR THE (N7) FUEL TANK PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (N10) FUEL TANK PRESSURE SENSOR RETURN CIRCUIT
- Measure the resistance between the (N7) Fuel Tank Pressure Sensor Signal circuit and the (N10) Fuel Tank Pressure Sensor Return circuit at the Fuel Tank Assembly in-line harness connector.
Is the resistance above 10k Ohms?
Yes
- Go To 6
No
- Repair the short between the (N7) Fuel Tank Pressure Sensor Signal circuit and the (N10) Fuel Tank Pressure Sensor Return circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance between the (N7) Fuel Tank Pressure Sensor Signal circuit and the (N10) Fuel Tank Pressure Sensor Return circuit at the Fuel Tank Assembly in-line harness connector.
- POWERTRAIN CONTROL MODULE (PCM)
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors for the Powertrain Control Module (PCM).
- Look for any chafed, pierced, pinched or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals.
- 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 .