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. Are any of the following displayed as current or have high past counts on the CONSULT screen:
  - P0563
  - P0687
  - P2503
  - P2504
Is applicable DTC detected?

YES

Refer to DTC Index .

NO

GO TO 2 .
CHECK DTC PRIORITY
1. Turn ignition switch ON.
2. Connect CONSULT and check for ENGINE diagnostic trouble codes.
3. Check for DTC P009D being current on the CONSULT screen.
Is DTC P009D detected as current?

YES

GO TO 3 .

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 4 .

NO

Repair or replace error-detected parts.
CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Connect a jumper wire between fuel pressure relief valve harness connector F122 terminal 2 and ground.
3. Crank the engine 3-4 times.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did P009C DTC become current and P009D become past?

YES

GO TO 5 .

NO

GO TO 6 .
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 P009D 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 7 .

NO

Repair or replace error-detected parts.
CHECK THE ECM RESPONSE
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector F101.
3. Connect a jumper wire between ECM harness connector F101 terminal 97 and ground.
4. Turn ignition switch ON.
5. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did P009C DTC become current and P009D become past?

YES

GO TO 8 .

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 9 .

Repair or replace the engine harness for a short.

CHECK FOR AN OPEN 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 the fuel pressure relief valve harness connector F122 terminal 2.

ECM		Fuel pressure relief valve		Resistance
Connector	Terminal	Connector	Terminal	Resistance
F101	97	F122	2	< 10 Ω

Is resistance less than 10 ohms?

YES

GO TO 10 .

Repair or replace the engine harness for an open.

CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Connect all components.
3. Start the engine and idle for 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did P009D 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.