Diagnosis Procedure

WARNING: This page is about a different car, the 2018 Nissan Titan XD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC PRIORITY
1. Turn ignition switch ON.
2. Connect CONSULT and check for ENGINE diagnostic trouble codes.
3. Check for DTC P009C-00 being current on the CONSULT screen.
Is DTC P009C-00 detected as current?

YES

GO TO 2 .

NO

Refer to Intermittent Incident .
INSPECT FUEL PRESSURE RELIEF VALVE AND CONNECTOR PINS
1. Turn ignition switch OFF.
2. Disconnect fuel pressure relief valve harness connector F122.
3. Inspect the harness connector and fuel pressure relief valve pins for the following:
  - Loose connector
  - Corroded pins
  - Bent or broken pins
  - Pushed back or expanded pins
  - Moisture in or on the connector
  - Missing or damaged connector seals
  - Dirt or debris on or in the connector pins
  - Connector shell broken
  - Wire insulation damage
  - Damaged connector locking tab
Is the inspection result normal?

YES

GO TO 3 .

NO

Repair or replace error-detected parts.
CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Disconnect fuel pressure relief valve harness connector F122.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did P009D-00 DTC become current and P009C-00 become past?

YES

GO TO 4 .

NO

GO TO 5 .
CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Connect fuel pressure relief valve harness connector F122.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did P009C-00 DTC become current?

YES

Replace fuel pressure relief valve. Refer to Removal and Installation .

NO

The removal and installation of the connector corrected the fault.
INSPECT ECM AND HARNESS CONNECTOR PINS
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector F101.
3. Inspect the ECM connector pins for the following:
  - Loose connector
  - Corroded pins
  - Bent or broken pins
  - Pushed back or expanded pins
  - Moisture in or on the connector
  - Missing or damaged connector seals
  - Dirt or debris on or in the connector pins
  - Connector shell broken
  - Wire insulation damage
  - Damaged connector locking tab
Is the inspection result normal?

YES

GO TO 6 .

NO

Repair or replace error-detected parts.
CHECK THE ECM RESPONSE
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector F101.
3. Turn ignition switch ON.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did P009D-00 DTC become current and P009C-00 become past?

YES

GO TO 7 .

NO

Replace ECM. Refer to Removal and Installation .

CHECK FOR A PIN-TO-PIN SHORT CIRCUIT IN THE ENGINE HARNESS

Turn ignition switch OFF.
Disconnect the ECM harness connector F101.
Disconnect the fuel pressure relief valve harness connector F122.

Measure the resistance between the ECM harness connector terminal 97 and all other terminals in the ECM harness connector F101.

ECM		ECM		Resistance
Connector	Terminal	Connector	Terminal	Resistance
F101	97	F101	All	> 100k Ω

Is resistance greater than 100k ohms?

YES

GO TO 8 .

Repair or replace the engine harness for a short.

CHECK FOR A PIN-TO-GROUND SHORT CIRCUIT IN THE ENGINE HARNESS

Turn ignition switch OFF.
Disconnect the ECM harness connector F101.
Disconnect the fuel pressure relief valve harness connector F122.

Measure the resistance between the ECM harness connector F101 terminal 97 and ground.

ECM		Ground	Resistance
Connector	Terminal
F101	97	-	> 100k Ω

Is resistance greater than 100k ohms?

YES

GO TO 9 .

Repair or replace the engine harness for a short to ground.

CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Connect all components.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did P009C-00 DTC become current?

YES

Troubleshooting procedures need to be repeated from the beginning. A failure mode should have been be detected.

NO

The removal and installation of the connector corrected the fault.