Diagnosis Procedure
WARNING: This page is about a different car, the 2018 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK MIC IN SIGNAL CIRCUIT AND MIC VCC CIRCUIT CONTINUITY
- Turn ignition switch OFF.
- Disconnect TCU connector M173 and microphone connector R22.
- Check continuity between TCU connector M173 and microphone connector R22.
TCU
Microphone
Continuity
Connector
Terminal
Connector
Terminal
M173
16
R22
2
Yes
17
1
18
4
- Check the continuity between TCU connector M173 and ground.
TCU
Ground
Continuity
Connector
Terminal
M173
17
-
No
18
Is the inspection result normal?
YES
GO TO 2.
NO
Repair or replace harness or connectors.
- CHECK MIC VCC VOLTAGE
- Connect TCU connector M173 and microphone connector R22.
- Turn ignition switch ON.
- Check voltage between terminals of TCU connector M173.
TCU connector M173
Voltage
(Approx.)
(+)
(-)
Terminal
Terminal
18
16
5.0 V
Is the inspection result normal?
YES
GO TO 3.
NO
Replace TCU. Refer to Removal and Installation .
- CHECK MIC IN SIGNAL
Check signal between terminals of TCU connector M173.
TCU connector M173
Condition
Reference value
(+)
(-)
Terminal
Terminal
17
16
Speak into microphone.
Is the inspection result normal?
YES
Replace TCU. Refer to Removal and Installation .
NO
Replace microphone. Refer to Removal and Installation .