Diagnosis Procedure

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the voltage between ECM harness connector terminals under the following conditions.
   CONNECTOR TERMINAL VOLTAGE CHART
   
   

   ECM				Voltage
   +		-
   Connector	Terminal	Connector	Terminal
   F106	93	M6	128	Battery voltage

   Fig 1: Checking Voltage Between ECM Harness Connector Terminals

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

   Is the inspection result normal? 

   YES: GO TO  3.

   NO: GO TO 2.

Check the following.

• Harness connectors F12, F3
• 20 A fuse (No. 77)
• IPDM E/R harness connector E8
• Harness for open or short between ECM and battery

  Repair or replace harness or connectors.

Refer to "DESCRIPTION ".

Is the inspection result normal? 

YES: GO TO 4.

NO: Repair or replace harness or connectors.

1. Turn ignition switch ON.
2. Erase DTC.
3. Perform DTC Confirmation Procedure.

   See "DTC LOGIC ".

   Is the 1st trip DTC P0603 displayed again? 

   YES: GO TO 5.

   NO: INSPECTION END

1. Replace ECM.
2. Go to "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : SPECIAL REPAIR REQUIREMENT ".

   INSPECTION END