P0603
DTC P0603 ECM POWER SUPPLYComponent Description
Battery voltage is supplied to the ECM even when the ignition switch is turned OFF for the ECM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc.
On Board Diagnosis Logic
DTC Confirmation Procedure
NOTE: If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
1. Turn ignition switch ON and wait at least 1 second.
2. Start engine and let it idle for 1 second.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Repeat steps 2 and 3 for four times.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to "Diagnosis Procedure".
Wiring Diagram
EC-ECM/PW-01:
Diagnosis Procedure
