NO.1 NO RADIO RECEPTION (AM/FM)/NO OR LOW VOLUME

id0903a3804300

1

No radio reception (AM/FM) / no or low volume / Possible DTC: 09:Er20, 09:Er22

POSSIBLE CAUSE

• Jamming from aftermarket electronic equipment (two-way radio, navigation system, mobile phone, etc.)
• Audio unit malfunction
• Poor connection of antenna feeder plug
• Antenna feeder malfunction
• Open or short circuit in wiring harness between audio unit and manual antenna (antenna amplifier power supply system)
• Electronic jamming from outside, or inferior condition of broadcasting station radio wave
• Antenna rod is not installed (standard parts)

Diagnostic procedure

STEP

INSPECTION

ACTION

1
• Turn the audio unit on.
• Is the LCD indicated correctly?
Yes
Go to Step 3.
No
Go to the next step.
2
• Measure the voltage at B+ and ACC terminals.
• Is the voltage normal?
Specification

With ignition switch ON: 11.5 V or more

At idling: 12.5 V or more

Yes
Go to the next step.
No
Follow the diagnostic procedure for symptom No. 2 (Entire audio system).
3
• Set the volume between 10 and 15.
• Is a buzzing sound or voice confirmed?
Yes
Go to the next step.
No
Follow the diagnostic procedure for symptom No. 3 (Entire audio system) or No. 4 (Entire audio system).
4
• Tune to a local broadcasting station and check the reception condition.
• Is the reception normal?
Yes
Go to the next step.
No
Go to Step 6.
5
• Push the PRESET buttons and check the preset conditions.
• Have preset stations been stored?
Yes
The system is normal.
No
Preset broadcasting stations.
6
• Is aftermarket electronic equipment (two-way radio, navigation system, mobile phone, etc.) installed?
Note
• A TV antenna located close to the audio antenna can be the cause of noise. Relocate the TV antenna.
Yes
Go to the next step.
No
Go to Step 8.
7
• Remove aftermarket electronic equipment.
• Turn the audio unit on and check the reception condition.
• Does reception improve?
Yes
The system is normal.
(Explain to the customer that aftermarket electronic equipment is the cause of the noise)
No
Go to the next step.
8
• Refer to confirmation Step 3, and inspect the antenna system.
• Is a whirring sound present?
Yes
Replace the audio unit.
No
Go to the next step.
9
• Inspect the antenna feeder plug connection condition.
• Is the connection normal?
Yes
Go to the next step.
No
Insert the antenna feeder plug securely.
10
• Turn the ignition switch to the LOCK position.
• Measure the continuity between the antenna feeder axis and ground.
• Is there any continuity?
Yes
Replace the antenna feeder.
No
Go to the next step.
11
• Measure the voltage at audio unit terminal H (24-pin) to verify the antenna amplifier power supply.
• Is the voltage B+?
Yes
Go to the next step.
No
Replace the audio unit.
12
• Turn the ignition switch to the LOCK position.
• Inspect the continuity between audio unit terminal H (24-pin) and manual antenna terminal A.
• Is there any continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness between the audio unit and the manual antenna (antenna amplifier power supply system), then verify the reception condition.
If the reception has improved, troubleshooting is completed.
If the reception has not improved, go to the next step.
13
• Compare the reception with another audio unit on the same model (model/unit) under the same problem conditions.
• Is the reception equivalent to the customer's unit?
Note
• Due to the following differences, you may sense a difference in reception efficiency.

(Vehicle factor)

- Antenna installation location, height, feeder wiring routing, optional electrical equipment

(Audio unit factor)

- High-tone setting: Decreases effective volume range when signals become weak. (Noise is easy to be conspicuous)
- Noise restraint setting: Widens effective volume range when signals become weak. (Noise is not conspicuous.)
Yes
The system is normal.
(It is caused by electronic jamming from outside, or inferior broadcasting station signal condition.)
No
Replace audio unit.