NAVIGATION SYSTEM (for Navigation Receiver Type) Microphone Circuit between Microphone and Navigation Receiver Assembly

DESCRIPTION

• The navigation ECU sub-assembly and map light assembly (telephone microphone assembly) are connected to each other using the microphone connection detection signal lines.

• Using this circuit, the navigation ECU sub-assembly sends power to the map light assembly (telephone microphone assembly), and the map light assembly (telephone microphone assembly) sends microphone signals to the navigation ECU sub-assembly.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (NAVIGATION ECU SUB-ASSEMBLY - MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY))

   
   

   1. Disconnect the L27 navigation ECU sub-assembly connector.

   2. Disconnect the U3 map light assembly (telephone microphone assembly) connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition L27-4 (MACC) - U3-5 (MACC) Always Below 1 Ω L27-5 (MIN+) - U3-4 (MCO+) Always Below 1 Ω L27-19 (MIN-) - U3-3 (MCO-) Always Below 1 Ω L27-6 (SNS2) - U3-2 (SNS2) Always Below 1 Ω L27-4 (MACC) - Body ground Always 10 kΩ or higher L27-5 (MIN+) - Body ground Always 10 kΩ or higher L27-19 (MIN-) - Body ground Always 10 kΩ or higher L27-18 (SGND) - Body ground Always 10 kΩ or higher L27-6 (SNS2) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

2. INSPECT NAVIGATION ECU SUB-ASSEMBLY

   
   

   1. Reconnect the L27 navigation ECU sub-assembly connector.

   2. Reconnect the U3 map light assembly (telephone microphone assembly) connector.

   3. 

      Text in Illustration

      *a	Component with harness connected (Navigation ECU Sub-assembly)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition L27-4 (MACC) - Body ground Power switch on (ACC) 4 to 6 V

   4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition L27-18 (SGND) - Body ground Always Below 1 Ω L27-19 (MIN-) - Body ground Always Below 1 Ω

   
   

   NG

   INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY) Click here

   OK

   REPLACE NAVIGATION ECU SUB-ASSEMBLY Click here

3. INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)

   
   

   1. Disconnect the U3 map light assembly (telephone microphone assembly) connector.

   2. 

      Text in Illustration

      *a	Component without harness connected (Map Light Assembly (Telephone Microphone Assembly))

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition U3-2 (SNS2) - U3-3 (MCO-) Always Below 1 Ω

   
   

   NG

   REPLACE TELEPHONE MICROPHONE ASSEMBLY Click here

   OK

4. INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)

   
   

   1. Reconnect the L27 navigation ECU sub-assembly connector.

   2. 

      Text in Illustration

      *a	Component without harness connected (Map Light Assembly (Telephone Microphone Assembly))

      Reconnect the U3 map light assembly (telephone microphone assembly) connector.

   3. Turn the power switch on (ACC).

   4. Connect an oscilloscope to terminals 4 (MCO+) and 3 (MCO-) of the U3 map light assembly (telephone microphone assembly) connector.

   5. Check the waveform of the telephone microphone assembly using the oscilloscope.

      Result
      Result Proceed to A waveform synchronized with the voice input to the map light assembly (telephone microphone assembly) is output A A waveform synchronized with the voice input to the map light assembly (telephone microphone assembly) is not output B

   
   

   B

   REPLACE TELEPHONE MICROPHONE ASSEMBLY Click here

   A

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

5. REPLACE TELEPHONE MICROPHONE ASSEMBLY

   
   

   1. Replace the telephone microphone assembly Click here.

   2. Check if the same malfunction recurs.

      Result
      Result Proceed to Malfunction does not recur (returns to normal) A Malfunction recurs B

   
   

   B

   REPLACE MAP LIGHT ASSEMBLY Click here

   A

   END