Audio System DTC Troubleshooting: 1406
DTC 1406: Audio Error 6 (Radio Error)
NOTE:
Check the vehicle battery condition first.
This audio DTC sets when Connection NG is indicated in the tuner unit diagnosis (the Remote Tuner icon is red in the System Links).
Before you troubleshoot, make sure to follow the General Troubleshooting Information.
1.
Problem verification:

Problem verification
?1.
Clear the hard error codes.

?2.
Turn the vehicle to the OFF (LOCK) mode, then the ON mode.

?3.
Check for hard error codes.

Is DTC 2612 indicated with DTC 1406?

     
YES
     
     
     
The failure is duplicated, go to step 2.
     
NO: Only DTC 1406 is indicated
     
     
     
The failure is duplicated, go to step 7.
     
NO: DTC is not indicated
     
     
     
Intermittent failure, the system is OK at this time.?
2.
Determine possible failure area (related unit, others):

Determine possible failure area (related unit, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Multi-information display unit connector A (12P)

?3.
Clear the hard error codes.

?4.
Turn the vehicle to the ON mode.

?5.
Go into the System Diagnostic Mode, and select the Error History icon from the System Links.

Is DTC 1406 indicated?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
3.
Shorted wire check (GA BUS+ line, GA BUS?line):

Shorted wire check (GA BUS+ line, GA BUS?line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Audio unit connector D (12P)
Tuner unit connector A (12P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector D (12P): disconnected
 
Multi-information display unit connector A (12P): disconnected
 
Tuner unit connector A (12P): disconnected
 
Test point 1
Tuner unit connector A (12P) No. 7
Test point 2
Body ground

Test point 1
Tuner unit connector A (12P) No. 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
There is a short to body ground in the GA BUS wire(s). Replace the affected shielded harness.?
     
NO
     
     
     
The GA BUS+ and the GA BUS? wires are not shorted to ground. Go to step 4.
4.
Shorted wire check (GA BUS+ line to GA BUS? line):

Shorted wire check (GA BUS+ line to GA BUS? line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector D (12P): disconnected
 
Multi-information display unit connector A (12P): disconnected
 
Tuner unit connector A (12P): disconnected
 
Test point 1
Tuner unit connector A (12P) No. 7
Test point 2
Tuner unit connector A (12P) No. 1

Is there continuity?

     
YES
     
     
     
There is a short in the GA BUS wires. Replace the affected shielded harness.?
     
NO
     
     
     
The GA BUS+ and the GA BUS? wires are not shorted. Go to step 5.
5.
Shorted wire check (SH GA BUS line to another lines):

Shorted wire check (SH GA BUS line to another lines)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector D (12P): disconnected
 
Multi-information display unit connector A (12P): disconnected
 
Tuner unit connector A (12P): disconnected
 
Test point 1
Tuner unit connector A (12P) No. 2
Test point 2
Tuner unit connector A (12P) No. 7


Is there continuity?

     
YES
     
     
     
There is a short in the GA BUS wires. Replace the affected shielded harness.?
     
NO
     
     
     
The SH GA BUS wire is OK. Go to step 6.
6.
Open wire check (GA BUS+ line, GA BUS? line):

Open wire check (GA BUS+ line, GA BUS? line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector D (12P): disconnected
 
Multi-information display unit connector A (12P): disconnected
 
Tuner unit connector A (12P): disconnected
 
Test point 1
Audio unit connector D (12P) No. 7
Test point 2
Tuner unit connector A (12P) No. 7


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
There is an open in the wire(s) between the audio unit and the tuner unit. Replace the affected shielded harness.?
7.
Determine possible failure area (GA +B line, others):

Determine possible failure area (GA +B line, others)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Test point 1
Tuner unit connector A (12P) No. 12
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
The GA +B wire is OK. Go to step 8.
     
NO
     
     
     
Go to step 11.
8.
Determine possible failure area (GA GND line, others):

Determine possible failure area (GA GND line, others)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Test point 1
Tuner unit connector A (12P) No. 6
Test point 2
Body ground

Is there less than 0.2 V?

     
YES
     
     
     
The GA GND wire is OK. Go to step 9.
     
NO
     
     
     
Go to step 13.
9.
Determine possible failure area (GA SYS ON line, others):

Determine possible failure area (GA SYS ON line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Test point 1
Tuner unit connector A (12P) No. 8
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
The GA SYS ON wire is OK. Go to step 10.
     
NO
     
     
     
Go to step 14.
10.
Open wire check (GA BUS+ line, GA BUS? line):

Open wire check (GA BUS+ line, GA BUS? line)
?1.
Disconnect the following connectors.
Audio unit connector D (12P)
Tuner unit connector A (12P)

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector D (12P): disconnected
 
Tuner unit connector A (12P): disconnected
 
Test point 1
Audio unit connector D (12P) No. 7
Test point 2
Tuner unit connector A (12P) No. 7


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
There is an open in the wire(s) between the audio unit and the tuner unit. Replace the affected shielded harness.?
11.
Open wire check (GA +B line):

Open wire check (GA +B line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
Audio unit connector D (12P) No. 12
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
Repair an open in the wire between the audio unit and the tuner unit.?
     
NO
     
     
     
The GA +B wire is not open. Go to step 12.
12.
Shorted wire check (GA +B line):

Shorted wire check (GA +B line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Audio unit connector D (12P)
Tuner unit connector A (12P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector D (12P): disconnected
 
Tuner unit connector A (12P): disconnected
Test point 1
Tuner unit connector A (12P) No. 12
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to body ground in the wire between the audio unit and the tuner unit.?
     
NO
     
     
     
13.
Open wire check (GA GND line):

Open wire check (GA GND line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Test point 1
Audio unit connector D (12P) No. 6
Test point 2
Body ground

Is there any voltage?

     
YES
     
     
     
     
NO
     
     
     
Repair an open or high resistance in the wire between the audio unit and the tuner unit.?
14.
Open wire check (GA SYS ON line):

Open wire check (GA SYS ON line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Test point 1
Audio unit connector D (12P) No. 8
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
Repair an open in the wire between the audio unit and the tuner unit.?
     
NO