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 P040C-00 being current on the CONSULT screen.
Is applicable DTC detected?

YES

GO TO 2 .

NO

Refer to Intermittent Incident .
INSPECT EGR TEMPERATURE SENSOR AND CONNECTOR PINS
1. Turn ignition switch OFF.
2. Disconnect EGR temperature sensor from engine harness connector F142.
3. Inspect the engine harness and EGR temperature sensor 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 3 .

NO

Repair or replace error-detected parts.
CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Disconnect the EGR temperature sensor from the engine harness connector F142.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P040D-00 become current and DTC P040C-00 become past?

YES

GO TO 4.

NO

GO TO 5 .
CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Connect EGR temperature sensor to the engine harness connector F142.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P040C-00 become current?

YES

Replace the EGR temperature sensor. Refer to Removal and Installation .

NO

The removal and installation of the connector corrected the issue.
INSPECT ECM AND ENGINE HARNESS CONNECTOR PINS
1. Turn ignition switch OFF.
2. Disconnect ECM from engine 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 CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Disconnect the engine harness connector F101 from the ECM.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P040D-00 become current and DTC P040C-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 engine harness from the ECM connector F101.
Disconnect the EGR temperature sensor from the engine harness connector F142.

Measure the resistance between the EGR temperature sensor SIGNAL terminal 174 in the engine harness ECM connector and all other terminals in the engine harness ECM connector F101.

ECM		ECM		Resistance
Connector	Terminal	Connector	Terminal	Resistance
F101	174	F101	All	> 100k Ω

Is resistance greater than 100k ohms?

YES

Repair or replace the engine harness for an open.

GO TO 8 .

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

Turn ignition switch OFF.
Disconnect the engine harness from the ECM connector F101.
Disconnect the EGR temperature sensor from the engine harness connector F142.

Measure the resistance between the EGR temperature sensor SIGNAL terminal 174 in the engine harness ECM connector F101 and ground.

ECM		Ground	Resistance
Connector	Terminal
F101	174	-	> 100k Ω

Is resistance greater than 100k ohms?

YES

GO TO 9 .

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

CHECK DTC PRIORITY
1. Connect all components.
2. Turn ignition switch ON.
3. Connect CONSULT and check for ENGINE diagnostic trouble codes.
4. Check for DTC P040C-00 being past on the CONSULT screen.
Is the inspection result normal?

YES

The removal and installation of the connector corrected the issue.

NO

GO TO 2 .