Toyota PT546-00140 User manual

14Scion Display Audio
PT546-00140
TROUBLESHOOTING GUIDE Rev A：5/17/2013

AUDIO MAINUNIT TROUBLESHOOTING
APPLY TO: PT546-00140
HINT:
This inspection procedure is a simple troubleshooting that should be carried out on the
vehicle during system operation and was prepared on the assumption of system component
troubles (except for the wires and connectors, etc.).
Always inspect the trouble taking the following into consideration.
*Open or short circuit of the wire harness
*Connector or terminal connection fault
No.
PROBLEM
1
GENERAL
No power coming in.
2
One or more speakers do not work.
3
Sound quality poor.
4
RADIO
Power coming in, but radio not operating.
5
Either AM or FM does not work.
5
Reception poor (volume faint).
5
Few preset tuning bands.
6
Sound quality poor.
7
Cannot set station select button.
7
Preset memories disappear.
8
Analog reception can receive but, HD radio can not receive.
9
HD reception is poor and sound is mute frequently.
10
CD PLAYER
CD cannot be inserted.
11
Power coming in, but CD player not operating.
12
Sound jumps.
13
Sound quality poor (Volume faint).
14
CD will not eject.
15
NOISE
Noise produced by vibration or shock while driving.
16
Noise produced when engine starts.
17
Noise heard occasionally.
18
AUX
Cannot select AUX mode.
19
Sound quality poor (Volume faint).
20
ASL
ASL ineffective (sound level will not increase).
21
USB
Sound quality poor.
22
USB device connected, but cannot select USB mode.
23
iPod/USB
Head unit can play USB devices, but not iPod.
24
iPod
Head unit can operate iPod, but not charge it.
25
Bluetooth
Bluetooth setup menu is not displayed.
26
MAP Screen
MAP Screen is not displayed.

1
GENERAL
No power coming in.
Check if the fuse is OK.
Is ACC applied to head unit?
Is +B applied to head unit?
Check if GND (wire harness side) to
head unit is OK?
Head unit faulty.
Replace fuse.
ACC wire harness faulty.
+B wire harness faulty.
GND faulty.
Yes
No
No
Yes
No
No
Yes
Yes

2
GENERAL
One or more speakers do not work.
Is there continuity in the speaker wire
harness?
Temporarily install another speaker.
Is the function OK?
Head unit faulty.
Speaker wire harness faulty.
Speaker faulty.
Yes
No
No
Yes
No
Yes
Check volume control.
Check fade, balance settings.
Check for proper connection to head unit.
Head unit faulty.
Yes
No
No
Yes
Yes
No
Head unit faulty.
Please connect proper to head unit.
Do non-functioning speakers produce hiss?
Head unit faulty.

3
GENERAL
Sound quality poor.
Head unit faulty.
Yes
Yes
Are all the connectors for speakers connected?
Speaker wire harness is faulty.
Check fade, balance settings.
No
Please set up a fade and balance
settings correctly.
Yes
Check treble, bass settings.
No
Please set up a treble and bass
settings correctly.
Dose the setting of the vehicle type match?
Please set up a vehicle type
correctly.
No
Yes
Check input the device.
Check for bad speakers.
No
No
No
Input device is faulty.
Yes

4
RADIO
Power coming in, but radio not operating.
Is CD player operating normally?
Is there continuity in speaker wire harness?
Temporarily install another speaker.
Is the function OK?
Head unit faulty.
5
RADIO
Either AM or FM does not work, reception poor (volume faint),
few preset tuning bands.
Problem with radio wave signals or location?
Are both AM and FM defective?
Head unit faulty.
Speaker wire harness faulty.
Speaker faulty.
Poor signals, poor location.
Head unit faulty.
Go to No.2
Yes
Yes
No
No
No
Yes
Yes
No
No
Yes
Check antenna installation to vehicle.
Check antenna connection to head-unit.
Yes
Yes
No
Please install a antenna
to vehicle.
Please connect a antenna
to head-unit.
No

6
RADIO
Sound quality poor.
Is sound quality always bad?
Is CD player operating normally?
Is the antenna properly installed?
Temporarily install another antenna.
Is the sound quality OK?
6-A
Is the sound quality certain?
Is the sound quality with other modes good?
Head unit faulty.
Go to step 6-A
Go to No.4
Install properly
Antenna faulty.
Head unit faulty.
Poor signals, poor location.
No
Yes
Yes
Yes
No
Yes
No
Yes
No
No

7
RADIO
Cannot set station select button, Preset memories disappear.
Can CD be inserted in CD player?
Check radio fuse is OK?
Are ACC and +B applied to head unit ?
8
RADIO
Analog reception can receive but, HD radio can not receive.
Is radio setting of HD active?
Problem with radio wave signals or location?
Is analog reception good?
Head unit faulty.
Replace fuse.
ACC and +B wire harness
faulty.
Check if GND (wire harness side) to head unit is
OK?
GND faulty.
Head unit faulty.
Set HD ON at audio
settings.
Poor signals, poor location.
Head unit faulty.
Go to No.6
Yes
No
No
No
Yes
Yes
No
Yes
Yes
No
Yes
No
No
Yes
Check if the station can broadcast HD.
Yes
The receiving station
which can broadcast HD.
No

9
RADIO
HD reception is poor and sound is mute frequently.
Problem with radio wave signals or location?
Is there continuity in antenna wire harness?
Is there analog reception is good?
9-A.
Is there continuity in speaker wire harness?
Temporarily install another speaker.
Is the function OK?
Head unit faulty.
Poor signals, poor location.
Antenna wire harness
faulty.
Head unit faulty.
Go to No.6
Speaker wire harness faulty.
Speaker faulty.
Yes
No
No
Yes
Yes
No
Yes
No
No
Yes

10
CD PLAYER
CD cannot be inserted.
Is CD already inserted?
Is +B applied to head unit ?
Is ACC applied to head unit ?
Check if GND (wire harness side) to head unit is
OK?
Head unit faulty.
Eject CD.
+B wire harness faulty.
ACC wire harness faulty.
GND wire harness faulty
Yes
No
Yes
Yes
Yes
No
No
No

11
CD PLAYER
Power coming in, but CD player not operating.
Is CD inserted correct side up?
Is the function OK if inserted different CD?
Is radio operating normally?
Is temperature inside interior panel hot?
Head unit faulty.
Insert CD the correct side up.
CD faulty.
Go to step 9-A
Protective circuit in operation.
It is necessary for the internal
temperature of the head unit until
to fall.
No
Yes
No
Yes
No
No
Yes
Yes
Is the correct CD type/shape inserted?
Insert the correct CD type/shape.
Yes
No

13
CD PLAYER
Sound quality poor (Volume faint).
12
CD PLAYER
Sound jumps.
Yes
Yes
No
No
Does sound jump only during strong vibration?
Jumping caused by vibration.
Functions OK if different CD inserted.
Head unit faulty.
Yes
Yes
No
No
Yes
Yes
No
No
Functions OK if another Disc inserted?
Check another modes: AM, FM, etc.
Is radio operating normally?
Disc faulty.
Is speaker properly installed?
Temporarily install another speaker.
Is the function OK?
Speaker faulty.
Install properly
Head unit faulty.
CD faulty.

14
CD PLAYER
CD will not eject.
15
NOISE
Noise produced by vibration or shock while driving.
Are connectors properly plugged into head unit?
No
No
No
Yes
No
Yes
Yes
Yes
Is +B applied to radio receiver assembly?
Check if radio fuse is OK?
Is ACC applied to radio receiver assembly?
Replace fuse.
+B wire harness faulty.
Check if GND (wire harness side) to radio
receiver assembly is OK?
GND wire harness faulty.
ACC wire harness faulty.
Head unit faulty.
Yes
No
Yes
Is speaker properly installed?
With vehicle stopped, lightly tap headunit.
Is noise produced?
No
Install properly.
Noise produced by static electricity accumulating
in the vehicle body.
No
Plug properly.
Yes
Head unit faulty.
Is antenna cable properly plugged into
head unit?
Yes
No
Plug properly.

16
NOISE
Noise produced when engine starts.
No
Yes
No
Whistling noise which becomes high-pitched
when accelerator strongly depressed,
disappears shortly after engine stops.
Possibility of
vehicle side factors.
Noise OK if another
head unit .
Head unit faulty.
.
Yes
No
Whistling noise occurs when A/C is operation.
Scratching noise occurs during sudden acceleration,
driving on rough roads or when ignition switch is
turned on.
Murmuring sound stops when engine stops.
Scratching noise occurs while engine is running and
continues a while even after engine stops.
Yes
Yes
Yes
Yes
No
No
No
Other type of noise.
Yes
No

17
NOISE
Noise heard occasionally.
oes the noise occur only in the radio?
Does the noise occur in a particular place?
Yes
Yes
No
No
No
Yes
No
Yes
Yes
No
Yes
No
Refer to No.13, No.15, No.16,
No.19, or No.21
Temporarily remove the additional
part. Does the noise stop?
Yes
Check the grounding of the antenna,
antenna cord, choke coil, and noise filter.
Is it OK?
Does the condition get better by exchanging
the choke coil?
Exchange the choke coil.
Does the noise occur even pulling out the
defogger terminal?
Does the noise occur even pulling out the
antenna terminal?
Does the noise occur even pulling out the
antenna cord from the headunit?
No
Correct grounding.
Processing the ground properly.
Mixing into the defogger cable.
Improvement of wiring routing
of defogger code.
The parts which added have a
problem. Use different parts.
Mixing into the antenna cable.
Improvement of wiring routing
of antenna code.
Is there any additional installation part
around the receiving antenna?
No
Yes
Electric wave environment with
the influence.
Head unit faulty.
Replace the product.
No
Yes

Yes
No
Yes
No
Does the condition get better by replacing
the antenna cord?
Exchange the antenna cord.
No
A noise jumps at the antenna cable line via a defogger terminal part from the outbreak
source and mixes it.
Please identify a noise source from the wiring around the defogger terminal.

18
AUX
Cannot select AUX mode.
Is the mini-plug from the portable audio
component properly connected to the car AUX
jack?
Is the AUX wire harness installed properly?
Install the AUX wire harness
properly.
Is there continuity in the AUX wire harness?
Temporarily install another AUX stereo jack
(adapter assy.).
Is the function OK?
Car AUX stereo jack faulty.
Head unit faulty.
Yes
No
Yes
Yes
No
Insert the mini-plug into the
car AUX jack properly.
No
AUX wire harness faulty.
No
Yes

19
AUX
Sound quality poor (volume faint).
Is the volume of the AUX component set to a
sufficient level?
Temporarily connect another stereo mini-plug
cable.
Is the function OK?
Stereo mini-plug cable faulty.
Is there continuity in the AUX wire harness?
Head unit faulty.
AUX wire harness faulty.
Yes
No
No
No
Adjust the volume of the AUX
component.
Yes
Yes

20
ASL
ASL ineffective (sound level will not increase).
Is the ASL setting OFF?
Change the ASL setting LOW or
higher.
Is the vehicle harness connected to the
head unit properly?
Connect the vehicle harnesses to
the head unit properly.
Temporarily install another head unit.
Is the function OK?
Head unit faulty.
Fault in the speed pulse signal line.
Check the speed pulse oscillation on the
signal wire.
Yes
No
No
No
Yes
Yes

21
USB
Sound quality poor.
Check if all other modes operate
normally.
Go to No.2
Is the CD sound quality normal?
Go to No.13
Temporarily install another head unit.
The sound quality still poor?
Check the files stored on
the USB device.
Head unit faulty.
No
No
Yes
No
Yes (poor)
Yes
No