Microphone Circuit between Microphone and Radio Receiver

AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM (w/o Daytime Running Light): Microphone Circuit between Microphone and Radio Receiver
- Microphone Circuit between Microphone and Radio Receiver

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))

(a) Disconnect the navigation ECU sub-assembly connector.

(b) Disconnect the map light assembly (telephone microphone assembly) connector.

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

Standard Resistance:

w/o Sliding Roof





w/ Sliding Roof





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. INSPECT NAVIGATION ECU SUB-ASSEMBLY

(a) Reconnect the navigation ECU sub-assembly connector.

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

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





Standard Voltage:





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

Standard Resistance:





Text in Illustration





NG -- REPLACE NAVIGATION ECU SUB-ASSEMBLY Removal
OK -- Continue to next step.

3. INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)

(a) Disconnect the map light assembly (telephone microphone assembly) connector.

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





Standard Resistance:

w/o Sliding Roof





w/ Sliding Roof





Text in Illustration





NG -- REPLACE TELEPHONE MICROPHONE ASSEMBLY
OK -- Continue to next step.

4. INSPECT MAP LIGHT ASSEMBLY (TELEPHONE MICROPHONE ASSEMBLY)

(a) Reconnect the navigation ECU sub-assembly connector.

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

(c) Turn the power switch on (ACC).

(d) Connect an oscilloscope to terminals 4 (MCO+) and 3 (MCO-) of the map light assembly (telephone microphone assembly) connector (w/o Sliding Roof).

(e) Connect an oscilloscope to terminals 5 (MCO+) and 4 (MCO-) of the map light assembly (telephone microphone assembly) connector (w/ Sliding Roof).





(f) Check the waveform of the telephone microphone assembly using the oscilloscope.

Result:





Text in Illustration





B -- REPLACE TELEPHONE MICROPHONE ASSEMBLY

A -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Problem Symptoms Table

5. REPLACE TELEPHONE MICROPHONE ASSEMBLY

(a) Replace the telephone microphone assembly (w/ Sliding Roof) Removal.

(b) Replace the telephone microphone assembly (w/o Sliding Roof) Removal.

(c) Check if the same malfunction recurs.

Result:





B -- REPLACE MAP LIGHT ASSEMBLY Removal

A -- END