Mazda 3 Service Manual: No.1 Car Navigation System Does Not Start Operation [Car Navigation System]

1

Even if the NAVI mode is selected, the car-navigation system screen does not display.

Possible DTC

—

POSSIBLE CAUSE

• NAVI button malfunction

• Power supply fuse (+B, ACC) burnt out

• Open or short circuit in power supply (+B, ACC, GND) wiring harness

• Open or short circuit in wiring harness between audio unit and car-navigation unit communication system

• Car-navigation unit malfunction

• Audio unit malfunction

Step

Inspection

Action

1

VERIFY MALFUNCTION SYMPTOM

• Turn the ignition switch to the ON position.

• Turn the audio unit power supply on and select the NAVI mode.

• Does the car-navigation system launch and the map screen display?

Yes

Go to Step 6.

No

Go to the next step.

2

DETERMINE IF MALFUNCTION CAUSE IS SWITCH

• Operate switches other than the NAVI button.

• Do the modes other than the NAVI mode switch normally?

Yes

Go to the next step.

No

Inspect the switch referring to the switch inspection procedure of the diagnostic assist function.

(See DIAGNOSTIC ASSIST FUNCTION [AUDIO].)

3

INSPECT CAR-NAVIGATION UNIT POWER SUPPLY

• Turn the ignition switch to the ACC position.

• Measure the voltage at the following terminals:

• Terminal 1H (+B)

• Terminal 1G (ACC)

• Is the voltage value the battery voltage?

Yes

Go to the next step.

No

• Inspect the ROOM 15 A or AUDIO 7.5 A fuse.

If the fuse is burned out:

• Inspect for a short to ground in the wiring harness between the ROOM 15 A fuse and car-navigation unit terminal 1H, or the AUDIO 7.5 A fuse and car-navigation unit terminal 1G, and perform repairs.

If the fuse is not damaged or burned out:

• Inspect for an open circuit in the wiring harness between the battery and car-navigation unit terminal 1H or 1G.

4

INSPECT CAR-NAVIGATION UNIT GROUND

• Turn the ignition switch to the OFF position.

• Disconnect the audio unit connector.

• Verify the continuity between ground and the following terminal connectors 1A, 1B, 1C, and 1D on the wiring harness side.

• Is there continuity?

Yes

Go to the next step.

No

Inspect and repair the ground point for looseness, disengagement, or lifting.

Refer to the wiring diagram and verify whether or not there is a common connector between audio unit and ground.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

5

INSPECT CAR-NAVIGATION UNIT COMMUNICATION

• Turn the ignition switch to the ON position.

• Disconnect the audio unit connector.

• Inspect for malfunction between the following wiring harnesses.

• Audio unit terminal 5A and car-navigation unit terminal 2A

• Audio unit terminal 5B and car-navigation unit terminal 2B

• Audio unit terminal 5C and car-navigation unit terminal 2C

• Audio unit terminal 5D and car-navigation unit terminal 2D

• Is any malfunction verified?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between audio unit and car-navigation unit.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

No

Go to the next step.

6

DETERMINE IF MALFUNCTION CAUSE IS CAR-NAVIGATION UNIT

• Turn the ignition switch to the ON position.

• Launch the audio unit diagnostic assist function.

  (See DIAGNOSTIC ASSIST FUNCTION [AUDIO].)

• Select diagnostic assist code 16 external device connection information clearing.

• Turn the ignition switch to the OFF position.

• Turn the ignition switch to the ON position.

• Launch the audio unit diagnostic assist function.

  (See DIAGNOSTIC ASSIST FUNCTION [AUDIO].)

• Select diagnostic assist code 15 vehicle NAVI signal verification.

• Is NAVI (USB) NG displayed?

Yes

Replace the car-navigation unit.

(See CAR-NAVIGATION UNIT REMOVAL/INSTALLATION.)

No

Replace the audio unit.

(See AUDIO UNIT REMOVAL/INSTALLATION.)