Component Tests and General Diagnostics

CELLULAR COMMUNICATION: LEXUS LINK SYSTEM: ECU Power Source Circuit

ECU Power Source Circuit

DESCRIPTION

This circuit supplies power to operate the mayday ECU.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (IGN, ECU-B, ACC)
(a) Remove the ECU-B fuse from the engine room junction block.
(b) Remove the ACC and IGN fuses from the cowl side junction block RH.
(c) Measure the resistance of the fuses.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.

2. CHECK WIRE HARNESS (MAYDAY ECU - BATTERY AND BODY GROUND)




(a) Disconnect the U45 ECU connector.
(b) Measure the voltage and resistance of the wire harness side connector.
Standard voltage:






Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE MAYDAY ECU TOGETHER WITH MAYDAY BATTERY AND THEN PERFORM REGISTRATION