Nissan Sentra B18 (2020-2025) Service Manual: P0191 Frp Sensor

Dtc Description

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connectors

  • Fuel rail pressure sensor circuit is open or shorted.

  • Sensor power supply 2 is shorted.

• Fuel rail pressure sensor

• Each sensor, connected with sensor power supply 2 circuit

FAIL-SAFE

Not applicable

Confirmation Procedure

1. CHECK DTC PRIORITY

   DTC P0191 is displayed with DTCs related to crankshaft position sensor, first perform the trouble diagnosis of DTCs.

   Is applicable DTC detected?

   YES >>

   Perform diagnosis of applicable.

   NO >>

   GO TO 2.

2. PRECONDITIONING

   If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

   TESTING CONDITION:

   • Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.

   • Before performing the following procedure, check that the fuel tank is less than 1/8 full of fuel.

   >>

   GO TO 3.

3. PERFORM DTC CONFIRMATION PROCEDURE

   1. Start the engine and warm it up to the normal operating temperature.

      Note:

      Warm up the engine until “COOLANT TEMP/S” in “DATA MONITOR” mode in “ENGINE” of CONSULT reaches at least 70°C (158°F).

   2. Turn the ignition switch OFF and cool the engine until the engine coolant temperature reaches 35°C (95°F) or less.

      CAUTION:

      • The difference between air temperature and engine coolant temperature must be 5°C (9°F) or less.

      • Never turn ignition switch ON.

   3. Turn ignition switch ON and wait at least 60 seconds.

   4. Check 1st trip DTC.

   Is 1st trip DTC detected?

   YES >>

   Proceed to DTC Diagnosis Procedure.

   NO-1 >>

   To check malfunction symptom before repair: Refer to Intermittent Incident.

   NO-2 >>

   Confirmation after repair: INSPECTION END

Dtc Diagnosis Procedure

Turning the ignition switch ON with FRP sensor harness connector disconnected causes ECM to detect DTC P0190. Be sure to erase the DTC when the diagnosis procedure.

1. CHECK FUEL RAIL PRESSURE (FRP) SENSOR POWER SUPPLY-1

   1. Turn ignition switch OFF.

   2. Disconnect FRP sensor harness connector.

   3. Turn ignition switch ON.

   4. Check the voltage between FRP sensor harness connector terminals.

      FRP sensor			Voltage (Approx.)
      Connector	+	−
      	Terminal
      F101	1	3	5 V

   Is inspection result normal?

   YES >>

   GO TO 7.

   NO >>

   GO TO 2.

2. CHECK FRP SENSOR POWER SUPPLY-2

   Check the voltage between FRP sensor harness connector and ground.

   +		−	Voltage (Approx.)
   FRP sensor
   Connector	Terminal
   F101	1	Ground	5 V

   Is inspection result normal?

   YES >>

   GO TO 5.

   NO >>

   GO TO 3.

3. CHECK FRP SENSOR POWER SUPPLY CIRCUIT

   1. Turn ignition switch OFF.

   2. Disconnect ECM harness connector.

   3. Check the continuity between FRP sensor harness connector and ECM harness connector.

      FRP sensor		ECM		Continuity
      Connector	Terminal	Connector	Terminal
      F101	1	F24	43	Existed

   4. Also check harness for short to ground and short to power.

   Is the inspection result normal?

   YES >>

   GO TO 4.

   NO >>

   Repair or replace malfunctioning part.

4. CHECK SENSOR POWER SUPPLY 2 CIRCUIT

   Refer to Diagnosis Procedure.

   Is inspection result normal?

   YES >>

   Perform the trouble diagnosis for ECM power supply circuit. Refer to Diagnosis Procedure.

   NO >>

   Repair or replace malfunctioning part.

5. CHECK FRP SENSOR GROUND CIRCUIT

   1. Turn ignition switch OFF.

   2. Disconnect ECM harness connector.

   3. Check the continuity between FRP sensor harness connector and ECM harness connector.

      FRP sensor		ECM		Continuity
      Connector	Terminal	Connector	Terminal
      F101	3	F24	45	Existed

   4. Also check harness for short to power.

   Is the inspection result normal?

   YES >>

   GO TO 6.

   NO >>

   Repair or replace malfunctioning part.

6. CHECK ECM GROUND CIRCUIT

   Check the continuity between ECM harness connector and the ground.

   ECM		—	Continuity
   Connector	Terminal
   F24	5	Ground	Existed
   	65
   F25	69
   E16	157
   	159
   	162

   Is inspection result normal?

   YES >>

   INSPECTION END

   NO >>

   Repair or replace malfunctioning part.

7. CHECK FRP SENSOR SIGNSL CIRCUIT

   1. Turn ignition switch OFF.

   2. Disconnect ECM harness connector.

   3. Check the continuity between FRP sensor harness connector and ECM harness connector.

      FRP sensor		ECM		Continuity
      Connector	Terminal	Connector	Terminal
      F101	2	F24	44	Existed

   4. Also check harness for short to power.

   Is the inspection result normal?

   YES >>

   GO TO 8.

   NO >>

   Repair or replace malfunctioning part.

8. CHECK FRP SENSOR

   Check FRP sensor. Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   INSPECTION END

   NO >>

   Replace FRP sensor. Refer to Exploded View.

© 2014-2026 Copyright www.nisentra.com