P0193

P0193-FUEL PRESSURE SENSOR HIGH





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Powertrain Control Module (PCM) provides a 5-Volt supply to the Fuel Rail Pressure Sensor (RPS). The PCM also provides a ground on the sensor return circuit. The Fuel Rail Pressure Sensor provides a signal to the PCM on the Fuel Rail Pressure Sensor Signal circuit. This sensor signal voltage changes based on the pressure in the fuel rail. The PCM will detect a low signal voltage at low rail pressures. The PCM will detect a high signal voltage during high rail pressure conditions. The PCM will light the MIL lamp immediately after the diagnostic runs and fails. During this time the customer may experience a power and or speed derate. The PCM will turn off the MIL light after the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
With the ignition on and battery voltage greater than 10.4 Volts.

- Set Condition:
The circuit voltage to the Powertrain Control Module (PCM) is above a calibrated threshold for a certain period of time.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC

NOTE: If there are any 5-Volt supply DTCs present, repair those DTCs before proceeding.

1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECK THE (K181) SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the Fuel Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K181) FPS Signal circuit at the Fuel Pressure Sensor harness connector.

Is the reading above 5.2 volts?

Yes

- Repair the (K181) FPS Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK FOR THE (K181) SIGNAL CIRCUIT SHORTED TO THE (F857) 5-VOLT SUPPLY CIRCUIT




1. Turn the ignition off.
2. Disconnected PCM C1 harness connector.
3. Measure the resistance between the (K181) FPS Signal circuit and the (F857) 5-Volt Supply circuit at the Fuel Pressure Sensor harness connector.

Is the resistance below 10k Ohms?

Yes

- Repair the short between the (K181) FPS Signal circuit and the (F857) 5-Volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. CHECK THE (K181) SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE




1. Measure the resistance of the (K181) FPS Signal circuit between the Fuel Pressure Sensor harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the (K181) FPS Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

5. CHECK THE (K916) SENSOR GROUND FOR AN OPEN/HIGH RESISTANCE




1. Measure the resistance of the (K916) Sensor Ground circuit between the Fuel Pressure Sensor harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the (K916) Sensor Ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

6. CHECK THE FUEL PRESSURE SENSOR




1. Turn the ignition off.
2. Reconnect the PCM C1 harness connector.
3. Reconnect the Fuel Pressure Sensor harness connector.
4. Turn the ignition on.
5. With the scan tool, erase DTCs.
6. While monitoring scan tool, connect a jumper between the (K181) FPS Signal circuit and the (K916) Sensor Ground circuit at the Fuel Pressure Sensor harness connector.

Does the DTC P0192 set?

Yes

- Replace the Fuel Pressure Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.