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 on the CONSULT screen:
  - P0405-00
  - P0406-00
  - P0489-00
  - P0490-00
  - P0652-00
  - P0653-00
Is applicable DTC detected?

YES

Refer to DTC Index .

NO

GO TO 2 .
INSPECT EGR VALVE POSITION SENSOR AND CONNECTOR PINS
1. Turn ignition switch OFF.
2. Disconnect EGR valve position sensor harness connector F144.
3. Inspect the engine harness and EGR valve 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 EGR valve harness connector F144.
3. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P0406 become current?

YES

GO TO 4 .

NO

GO TO 6 .
CHECK THE CIRCUIT RESPONSE
1. Turn ignition switch OFF.
2. Disconnect EGR valve harness connector F144.
3. Connect a jumper wire between EGR valve harness connector F144 terminals 3 and 4.
4. Turn ignition switch ON and wait 30 seconds.
5. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P0405-00 become current?

YES

GO TO 5 .

NO

GO TO 6 .

CHECK THE SENSOR SUPPLY VOLTAGE AND RETURN CIRCUIT

Turn ignition switch OFF.
Disconnect the EGR valve harness connector F144.
Turn ignition switch ON.

Measure the voltage between EGR valve position sensor harness connector F144 terminals 2 and 3.

EGR valve

Voltage

(Approx.)

Connector

Terminal

F144

4.75V - 5.25V

Is inspection result normal?

YES

Replace the EGR valve. Refer to Removal and Installation .

GO TO 6.

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. Turn ignition switch ON and wait 30 seconds.
4. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P0406-00 become current?

YES

GO TO 8 .

NO

Replace ECM. Refer to Removal and Installation .
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 terminals 127 and 152.
4. Turn ignition switch ON and wait 30 seconds.
5. Connect CONSULT and check for current ENGINE diagnostic trouble codes.
Did DTC P0405-00 become current?

YES

GO TO 9 .

NO

Replace ECM. Refer to Removal and Installation .

CHECK THE SENSOR SUPPLY VOLTAGE AND RETURN CIRCUIT

Turn ignition switch OFF.
Disconnect the ECM harness connector F101.
Turn ignition switch ON.

Measure the voltage between ECM harness connector F101 terminals 106 and 127.

ECM

Voltage

(Approx.)

Connector

Terminal

F101

106

127

4.75V - 5.25V

Is inspection result normal?

YES

Repair or replace harness.

Replace ECM. Refer to Removal and Installation .