Diagnosis Procedure

WARNING: This page is about a different car, the 2013 Nissan Armada. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check voltage between ECM terminal 121 and ground with CONSULT or tester.
  Voltage: Battery voltage
  
  OK or NG
  
  OK: GO TO 3.
  
  NG: GO TO 2.
  
  Fig 1: Checking Voltage Between ECM Terminal 121 And Ground
  Courtesy of NISSAN NORTH AMERICA, INC.
DETECT MALFUNCTIONING PART
Check the following.
- IPDM E/R connector E121
- 20A fuse
- Harness for open or short between ECM and battery
  : Repair or replace harness or connectors.
CHECK INTERMITTENT INCIDENT
Refer to "HOW TO CHECK TERMINAL " and "INTERMITTENT INCIDENT ".

OK or NG

OK: GO TO 4.

NG: Repair or replace harness or connectors.
PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT
1. Turn ignition switch ON.
2. Select "SELF DIAG RESULTS" mode with CONSULT.
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
REPLACE ECM
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 " (With intelligent key system) or "ECM RE-COMMUNICATING FUNCTION: SPECIAL REPAIR REQUIREMENT " (Without intelligent key system).
3. Perform "VIN REGISTRATION ".
4. Perform "ACCELERATOR PEDAL RELEASED POSITION LEARNING ".
5. Perform "THROTTLE VALVE CLOSED POSITION LEARNING ".
6. < Flexible Fuel Vehicle >
  Perform "ETHANOL MIXTURE RATIO ADAPTATION (FLEXIBLE FUEL VEHICLE) ".
7. Perform "IDLE AIR VOLUME LEARNING ".
  :INSPECTION END