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 stored when one of the following occurs: 1) the telephone ECU assembly is malfunctioning; 2) the map light assembly is malfunctioning; 3) the microphone amplifier is malfunctioning; or 4) the wire harness between the telephone ECU assembly and map light is open or shorted.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK NAVIGATION SYSTEM
(a) Start the navigation system and check that the voice recognition microphone function operates normally.

Result





B -- GO TO NAVIGATION SYSTEM
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (TELEPHONE ECU ASSEMBLY - MAP LIGHT ASSEMBLY)





(a) Disconnect the P2 ECU connector.
(b) Disconnect the R7 map light connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR THEN CLEAR HISTORIC DTC
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (MAP LIGHT ASSEMBLY - BODY GROUND)





(a) Disconnect the R7 map light connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR THEN CLEAR HISTORIC DTC
OK -- Continue to next step.
4. CHECK MAP LIGHT ASSEMBLY (OPERATION)
(a) Temporarily replace the map light with a new or normally functioning one Removal.
(b) Check if DTC 4-3 is output.
OK:
DTC 4-3 is not output.
NG -- REPLACE TELEPHONE ECU ASSEMBLY TOGETHER WITH MAYDAY BATTERY
OK -- END (MAP LIGHT IS FAULTY; CLEAR HISTORIC DTC)
5. REPLACE TELEPHONE ECU ASSEMBLY TOGETHER WITH MAYDAY BATTERY
NEXT -- PERFORM REGISTRATION