Possible DTC

Does not switch to the night screen even though the light switch is in the TNS position.

POSSIBLE CAUSE

• Car-navigation unit malfunction

• TNS signal malfunction

• Open, short circuit in car-navigation unit terminal 1E

Step

Inspection

Action

1

• Launch the audio unit diagnostic assist function.

  (See DIAGNOSTIC ASSIST FUNCTION [AUDIO].)

• Select diagnostic assist code 15 vehicle NAVI signal verification.

• Does the TNS display OFF?

Yes

Go to the next step.

No

Go to Step 3.

2

• Measure the terminal voltage at audio unit connector (24-pin) terminal 1G.

• Is the voltage normal?

  Specification

  TNS ON: Approx. 12. V

  TNS OFF: Approx. 0 V

Yes

Go to the next step.

No

Inspect the applicable (TNS signal system) vehicle panel and repair or replace.

3

• Turn the light switch to the TNS position.

• Does the audio unit screen switch to the night screen?

Yes

System is normal.

No

Replace the audio unit.

(See AUDIO UNIT REMOVAL/INSTALLATION.)