DTC 4-3

CELLULAR COMMUNICATION: LEXUS LINK SYSTEM: 4-3: Overhead Module Microphone Error

DTC 4-3 - Overhead Module Microphone Error

DESCRIPTION

This DTC is output when one of the following occurs: 1) the mayday ECU assembly is malfunctioning; 2) the microphone assembly is malfunctioning; 3) the microphone amplifier assembly is malfunctioning; or 4) the wire harness between the mayday ECU assembly and the roof console box assembly is open or short.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK NAVIGATION SYSTEM
(a) Start the navigation system and check that the voice recognition microphone function operates normally.
(1) If the microphone function is normal, proceed to A.
(2) If the microphone function is malfunctioning, proceed to B.
B -- GO TO NAVIGATION SYSTEM
A -- Continue to next step.
2. CHECK WIRE HARNESS (MAYDAY ECU ASSEMBLY - ROOF CONSOLE BOX ASSEMBLY)




(a) Disconnect the M15 ECU connector.
(b) Disconnect the O2 roof console box connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK WIRE HARNESS (ROOF CONSOLE BOX ASSEMBLY - BODY GROUND)




(a) Disconnect the O2 roof console box connector.
(b) Measure the resistance of the wire harness side connector.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. REPLACE ROOF CONSOLE BOX ASSEMBLY
(a) Temporarily replace the roof console box assembly Removal with a new or normally functioning one.
(b) Check that the DTC 4-3 is output.
OK:
DTC 4-3 is not output.
NOTE:
If replacement of the ECU is necessary, replace the mayday battery (backup battery) together with the ECU. After the replacement, register the ECU Programming and Relearning.

NG -- REPLACE MAYDAY ECU ASSEMBLY
OK -- END