Diagnostic Test
WARNING: This page is about a different car, the 2013 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.
- ACTIVE DTC NOTE:
If there are any 5-Volt supply DTCs present, diagnose and repair those DTCs before proceeding.
- Turn the ignition on.
- With the scan tool, read DTCs.
Is the DTC active?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
- CHECK THE (K181) FUEL RAIL PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Turn the ignition off.
- Disconnect the FRPS harness connector.
- Turn the ignition on.
- Measure the voltage of the (K181) FRPS Signal circuit at the FRPS harness connector.
Is the reading above 5.2 volts?
Yes
- Repair the (K181) Fuel Rail Pressure Sensor Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 3
- CHECK THE (K181) FUEL RAIL PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE (F856) 5-VOLT SUPPLY CIRCUIT
- Turn the ignition off.
- Disconnected PCM C1 harness connector.
- Measure the resistance between the (K181) FRPS Signal circuit and the (F856) 5-Volt Supply circuit at the FRPS harness connector.
Is the resistance above 10k Ohms?
Yes
- Go To 3
No
- Repair the short between the (K181) Fuel Rail Pressure Sensor Signal circuit and the (F856) 5-Volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- CHECK THE (K181) FUEL RAIL PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- Measure the resistance of the (K181) FRPS Signal circuit between the FRPS harness connector and the PCM C1 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 5
No
- Repair the (K181) Fuel Rail Pressure Sensor Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- Measure the resistance of the (K181) FRPS Signal circuit between the FRPS harness connector and the PCM C1 harness connector.
- CHECK THE (K914) SENSOR GROUND FOR AN OPEN/HIGH RESISTANCE
- Measure the resistance of the (K914) Ground circuit between the FRPS harness connector and the PCM C1 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 6
No
- Repair the (K914) Sensor Ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- Measure the resistance of the (K914) Ground circuit between the FRPS harness connector and the PCM C1 harness connector.
- CHECK THE FUEL RAIL PRESSURE SENSOR
- Turn the ignition off.
- Reconnect the PCM C1 harness connector.
- Turn the ignition on.
- While monitoring scan tool, connect a jumper between the (K181) FRPS Signal circuit and the (K914) Sensor Ground circuit at the FRPS harness connector.NOTE:
The P018C-FUEL RAIL PRESSURE SENSOR CIRCUIT LOW DTC should become active or pending with the jumper in place.
Does the DTC display as described above?
Yes
- Replace the Fuel Rail Pressure Sensor in accordance with the service information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 7
- POWERTRAIN CONTROL MODULE (PCM)
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Rail Pressure Sensor and the Powertrain Control Module (PCM).
- Look for any chafed, pierced, pinched or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Fuel Rail Pressure Sensor and Control Module connectors.
- Perform any Technical Service Bulletins (TSBs) that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Replace and program the Powertrain Control Module in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .