Diagnosis Procedure

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check voltage between ECM terminal 121 and ground with CONSULT-III or tester.

   Voltage: Battery voltage 

   Fig 1: Checking Voltage Between ECM Terminal 121 And Ground

   Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

OK : GO TO  3.

NG : GO TO 2.

Check the following.

• 20A fuse
• IPDM E/R harness connector E121
• Harness for open or short between ECM and battery

Repair or replace harness or connectors.

Refer to "INTERMITTENT INCIDENT ".

OK or NG 

OK : GO TO 4.

NG : Repair open circuit or short to ground or short to power in harness or connectors.

With CONSULT-III 

1. Turn ignition switch ON.
2. Select "SELF DIAG RESULTS" mode with CONSULT-III.
3. Touch "ERASE".
4. Perform DTC Confirmation Procedure  .

   See "DTC CONFIRMATION PROCEDURE ".

5. Is the 1st trip DTC P0603 displayed again?

With GST 

1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Perform "DTC Confirmation Procedure"  .

   See "DTC CONFIRMATION PROCEDURE ".

4. Is the 1st trip DTC P0603 displayed again?

Yes or No 

Yes : GO TO 5.

No : INSPECTION END 

1. Replace ECM.
2. Perform initialization of NVIS (NATS) system and registration of all NVIS (NATS) ignition key IDs. Refer to "ECM RE-COMMUNICATING FUNCTION : SPECIAL REPAIR REQUIREMENT ".
3. Perform "VIN REGISTRATION ".
4. Perform "ACCELERATOR PEDAL RELEASED POSITION LEARNING ".
5. Perform "THROTTLE VALVE CLOSED POSITION LEARNING ".
6. Perform "IDLE AIR VOLUME LEARNING ".

INSPECTION END