Diagnosis Procedure
1.CHECK CONNECTOR
2.CHECK HARNESS FOR OPEN CIRCUIT
Check the resistance between the data link connector terminals.

BCM branch line circuit
M&A branch line circuitXenon headlamp
Description
OPERATION
Refer to EXL-10, "Component Description".
PRECAUTIONS FOR TROUBLE
DIAGNOSIS
Installation or removal of the connector must be done with the
lighting switch OFF.
When the lamp is illuminated (when the lighting switch is ON), do
not touch the harness, HID control ...
P0603 ECM power supply
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.
DTC Logic
DTC DETECTION LOGIC
DTC CON ...
Door key cylinder switch
Description
The main power window and door lock/unlock switch detects condition of the
door key cylinder switch and
transmits to BCM as the LOCK or UNLOCK signal.
Component Function Check
1.CHECK DOOR KEY CYLINDER SWITCH INPUT SIGNAL
Check KEY CYL UN-SW, KEY CYL UN-SW in "DATA MONITOR" mode ...