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P0192

P0192-FUEL PRESSURE SENSOR VOLTAGE TOO LOW


P0192 - Fuel Pressure Sensor Voltage Too Low:






WHEN MONITORED
With the ignition on and battery voltage greater than 10.4 volts.

SET CONDITION
The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.

POSSIBLE CAUSES
- Other DTC's
- Fuel pressure sensor
- (F855) 5-Volt supply circuit shorted to (G910) return circuit
- (K181) Signal circuit shorted to (G910) return circuit
- (K181) Signal circuit open
- (F855) 5-Volt supply circuit open
- (K181) Signal circuit shorted to ground
- (F855) 5-Volt supply circuit shorted to ground
- ECM
- Intermittent condition

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. OTHER DTC'S
Ignition on, engine not running.
With the scan tool, read DTCs.

Q: Do you have multiple DTC's?

YES: Repair other DTC's first. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
NO: Go To 2

2. (F855) 5-VOLT SUPPLY AND (K915) RETURN CIRCUIT





Turn the ignition off.
Disconnect the Fuel Pressure sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Ignition on, engine not running.
Measure the voltage between the (F855) 5-volt supply and (K915) return circuits of the Fuel pressure sensor harness connector.

Q: Is the voltage between 4.5 and 5.5 volts?

YES: Go To 3
NO: Go To 4

3. FUEL PRESSURE SENSOR
Reconnect the disconnected Fuel Pressure Sensor harness connector.
While monitoring scan tool, disconnect the Fuel Pressure sensor harness connector.

Q: Does the DTC P0193 set?

YES: Replace the Fuel Pressure Sensor. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
NO: Go To 4

4. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K915) RETURN CIRCUIT





Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Fuel Pressure sensor harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance between the (F855) 5-volt supply circuit and (K915) return circuit in the sensor harness connector.

Q: Is the resistance greater than 100 K Ohms?

YES: Go To 5
NO: Repair the shorted circuits. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

5. (K181) SIGNAL CIRCUIT SHORTED TO (K915) RETURN CIRCUIT





Measure the resistance between the (K181) signal circuit and (K915) return circuit in the sensor connector.

Q: Is the resistance greater than 100 K Ohms?

YES: Go To 6
NO: Repair the shorted circuits. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

6. (K181) SIGNAL CIRCUIT OPEN





Measure the resistance between the signal (K181) circuit in the sensor harness connector with the (K181) signal circuit in the ECM harness connector.

Q: Is the resistance less than 10 Ohms?

YES: Go To 7
NO: Repair the open (K181) signal circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

7. (F855) 5-VOLT SUPPLY CIRCUIT OPEN





Measure the resistance between the supply (F855) circuit in the sensor harness connector with the (F855) 5-volt supply circuit in the ECM harness connector.

Q: Is the resistance less than 10 Ohms?

YES: Go To 8
NO: Repair the open (F855) 5-volt supply circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

8. (K181) SIGNAL CIRCUIT SHORTED TO GROUND





Measure the resistance between the (K181) signal circuit in the sensor harness connector and battery negative.

Q: Is the resistance greater than 100 K Ohms?

YES: Go To 9
NO: Repair (K181) signal circuit shorted to ground. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

9. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND





Measure the resistance between the (F855) 5-volt supply circuit in the sensor harness connector and battery negative.

Q: Is the resistance greater than 100 K Ohms?

YES: Go To 10
NO: Repair (F855) 5-volt Supply circuit shorted to ground. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

10. ECM
Reconnect the disconnected Fuel pressure sensor harness connector and ECM harness connectors.
While monitoring scan tool, disconnect the Fuel Pressure sensor connector.

Q: Does the DTC P0193 set?

YES: Test Complete. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
NO: Replace the ECM. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1