DTC 4-3 Overhead Module Microphone Error: Wiring Diagram

1. 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: Go To Next Step 

1. Disconnect the M14 ECU connector.
2. Disconnect the O4 map light plate connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

Fig 2: Identifying M14 ECU Connector And O4 Map Light Plate Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR THEN CLEAR HISTORIC DTC 

OK: Go To Next Step 

1. Disconnect the O4 map light plate connector.
2. Measure the resistance of the wire harness side connector.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Specified Condition
   O4-1 (GND) - Body ground	Below 1 Ω

   Fig 3: Identifying O4 Map Light Plate Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS AND CONNECTOR THEN CLEAR HISTORIC DTC 

   OK: Go To Next Step 

3. CHECK MAP LIGHT PLATE ASSEMBLY 
   1. Temporarily replace the map light plate assembly with a new or normally functioning one.
   2. 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)