Last Modified: 4-30-2014 6.6 C Doc ID: RM000001EG1000X
Model Year: 2006 Model: LX470 Prod Date Range: [05/2005 -           ]
Title: CELLULAR COMMUNICATION: LEXUS LINK SYSTEM: 4-3; Overhead Module Microphone Error; 2006 MY LX470 [05/2005 -        ]

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 map light plate assembly is open or short.

DTC No.

DTC Detection Condition

Trouble Area

4 - 3

Communication or communication line is abnormal between mayday ECU and map light plate
  • Mayday ECU assembly
  • Microphone assembly
  • Microphone amplifier assembly
  • Map light plate assembly
  • Wire harness

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

2.

CHECK WIRE HARNESS (MAYDAY ECU ASSEMBLY - MAP LIGHT PLATE ASSEMBLY)

(a) Disconnect the M14 ECU connector.

(b) Disconnect the O4 map light plate connector.

(c) Measure the resistance of the wire harness side connectors.

Standard resistance:

Tester Connection

Specified Condition

M14-7 (TACC) - O4-11 (TACC)

Below 1 Ω

M14-7 (TACC) or O4-11 (TACC) - Body ground

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR THEN CLEAR HISTORIC DTC

OK

3.

CHECK WIRE HARNESS (MAP LIGHT PLATE ASSEMBLY - BODY GROUND)

(a) Disconnect the O4 map light plate connector.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:

Tester Connection

Specified Condition

O4-1 (GND) - Body ground

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR THEN CLEAR HISTORIC DTC

OK

4.

CHECK MAP LIGHT PLATE ASSEMBLY

(a) Temporarily replace the map light plate assembly with a new or normally functioning one.

(b) Check that the DTC 4-3 is output.

OK:

DTC 4-3 is not output.

NG

REPLACE MAYDAY ECU ASSEMBLY TOGETHER WITH MAYDAY BATTERY AND THEN PERFORM REGISTRATION

OK

END (MAP LIGHT PLATE ASSEMBLY IS FAULTY; CLEAR HISTORIC DTC)