Description
ECM has the memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the Idle Air Volume Learning value memory, etc. even when the ignition switch is turned OFF.

DTC DETECTION LOGIC
| DTC No. | Trouble diagnosis | DTC detecting condition | Possible cause | 
| P0603 | ECM BACK UP/CIRCUIT (ECM power supply circuit) | ECM back-up RAM system does not function properly. | 
 | 
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
Is 1st trip DTC detected?
YES >> Go to EC, "Diagnosis Procedure".
NO >> INSPECTION END
1.INSPECTION START
Is the 1st trip DTC P0603 displayed again?
YES >> GO TO 2.
NO >> INSPECTION END
2.REPLACE ECM
>> INSPECTION END
Camshaft valve clearance
   Inspection and Adjustment
INSPECTION
Perform inspection as follows after removal, replacement or installation of 
camshaft or valverelated parts, or if
there are unusual engine conditions regarding valve clearance.
	Remove rocker cover. 
	Measure the valve clearance with the following proced ...
   
Spark plug
   Exploded View
1. Ignition coil 2. Spark plug
Removal and Installation
REMOVAL
1. Remove ignition coil.
CAUTION:
Do not drop or shock ignition coil.
2. Remove spark plug using a suitable tool.
Diameter (a) : 14 mm (0.55 in)
CAUTION:
Do not drop or shock spark plug.
INSPECTION AFTER REM ...