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 P040D-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 F142.
3. Connect a jumper wire between EGR temperature sensor return terminal 1 and signal circuit terminal 2 at EGR temperature sensor connector F142.
4. Turn ignition switch ON and wait 30 seconds.
5. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P040C-00 become current and DTC P040D become past?

YES

GO TO 4 .

NO

GO TO 5 .
CHECK DTCS AND VERIFY SENSOR CONDITION
1. Turn ignition switch OFF.
2. Connect the EGR temperature sensor to the engine harness connector F142.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for ENGINE diagnostic trouble codes.
5. Check for DTC P040D being current on the CONSULT screen.
Is applicable DTC detected?

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 from the ECM.
3. Connect a jumper wire between EGR temperature sensor return terminal 170 and signal circuit terminal 154 at the ECM connector F101.
4. Turn ignition switch ON and wait 30 seconds.
5. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P040C-00 become current and DTC P040D-00 become past?

YES

GO TO 7 .

NO

Replace ECM. Refer to Removal and Installation .

CHECK FOR AN OPEN 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 ECM connector F101 EGR temperature sensor terminal 170 and the engine harness EGR temperature sensor connector F142 terminal 1.

ECM		EGR temperature sensor		Resistance
Connector	Terminal	Connector	Terminal	Resistance
F101	170	F142	1	< 10 Ω

Is resistance less than 10 ohms?

YES

GO TO 8 .

Repair or replace the engine harness for an open.

CHECK FOR AN OPEN 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 ECM connector F101 EGR temperature sensor SIGNAL terminal 154 and the engine harness EGR temperature sensor connector F142 terminal 2.

ECM		EGR temperature sensor		Resistance
Connector	Terminal	Connector	Terminal	Resistance
F101	154	F142	2	< 10 Ω

Is resistance less than 10 ohms?

YES

GO TO 9 .

Repair or replace the engine harness for an open.

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 154 in the engine harness ECM connector F101 and all other pins in the engine harness ECM connector F101.

ECM		ECM		Resistance
Connector	Terminal	Connector	Terminal	Resistance
F101	154	F101	All	> 100k Ω

Is resistance greater than 100k ohms?

YES

Repair or replace the engine harness for an open.

GO TO 10 .

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 P040D 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 .