Lexus IS250 · Service Manual BODY ELECTRICAL

PROBLEM SYMPTOMS TABLE

Troubleshooting

HINT:
  1. Before inspecting the suspected areas listed in the table below, check the fuse and relay.
  2. Before inspecting the suspected areas listed in the table below, check for DTCs.
  3. Methods used to verify the cause of the problem are listed in order of probability in the suspected area column.

Audio Function: 
Symptom
Suspected area
See page
Pressing power switch does not turn on system.
1. Proceed to "Pressing Power Switch does not Turn on System"
Click here
2. Radio receiver power source circuit
Click here
3. Integration control & panel assembly power source circuit
Click here
4. AVC-LAN circuit
Click here
5. Radio receiver
Click here
6. Integration control & panel assembly
Click here
Pressing power switch does not turn on system. (with
1. Proceed to "Pressing Power Switch does not Turn on System"
Click here
2. Radio receiver power source circuit
Click here
3. Multi-display power source circuit
Click here
4. AVC-LAN circuit
Click here
5. Radio receiver
Click here
6. Multi-display
Click here
Panel switch does not function.
1. Steering pad switch circuit
Click here
2. AVC-LAN circuit
Click here
3. Radio receiver
Click here
No sound can be heard from speakers (audio is mute).
1. AVC-LAN circuit
Click here
2. Radio receiver power source circuit
Click here
3. Integration control & panel assembly power source circuit
Click here
4. Proceed to "No Sound can be Heard from Speakers"
Click here
5. Stereo component amplifier power source circuit
Click here
6. Proceed to "Sound Signal Circuit between Radio Receiver and Stereo Component Amplifier"
Click here
7. Speaker circuit
Click here
8. Proceed to "Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier"
Click here
9. Stereo component amplifier
Click here
10. Radio receiver
Click here
11. Integration control & panel assembly
Click here
No sound can be heard from speakers (audio is mute).
1. AVC-LAN circuit
Click here
2. Radio receiver power source circuit
Click here
3. Multi-display power source circuit
Click here
4. Proceed to "No Sound can be Heard from Speakers"
Click here
5. Stereo component amplifier power source circuit
Click here
6. Proceed to "Sound Signal Circuit between Radio Receiver and Stereo Component Amplifier"
Click here
7. Speaker circuit
Click here
8. Proceed to "Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier"
Click here
9. Stereo component amplifier
Click here
10. Radio receiver
Click here
11. Multi-display
Click here
Only DVD sound cannot be heard or sound quality is
1. Proceed to "Sound Signal Circuit between Radio Receiver and Stereo Component Amplifier"
Click here
2. Stereo component amplifier
Click here
3. Radio receiver
Click here
Sound quality is bad in all modes (Volume is too low.)
1. Proceed to "Poor Sound Quality in All Modes (Low Volume)"
Click here
2. Speaker circuit.
Click here
3. Proceed to "Sound Signal Circuit between Radio Receiver and Stereo Component Amplifier"
Click here
4. Proceed to "Mute Signal Circuit between Radio Receiver and Stereo Component Amplifier"
Click here
ASL does not function.
Proceed to "Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter"
Click here
External device sound cannot be heard or sound quality is bad. (Stereo jack is used.)
1. Radio receiver power source circuit
Click here
2. Proceed to "Sound Signal Circuit between Radio Receiver and Stereo Jack Adapter"
Click here
3. Stereo jack adapter
Click here
4. Radio receiver
Click here
Abnormal noise occurs.
1. Proceed to "Noise occurs"
Click here
2. Stereo component amplifier
Click here
3. Radio receiver
Click here
Radio broadcast cannot be received or poor reception.
Proceed to "Radio Broadcast cannot be Received or Poor Reception"
Click here
CD cannot be inserted/played or CD is ejected right
1. Radio receiver power source circuit
Click here
2. Proceed to "CD cannot be Inserted/Played or CD is Ejected Right After Insertion"
Click here
CD cannot be ejected.
1. Radio receiver power source circuit
Click here
2. Proceed to "CD cannot be Ejected"
Click here
Sound quality is bad only when CD is played. (Volume
Proceed to "Sound Quality is Bad Only when CD is Played (Volume is Too Low)"
Click here
CD sound skips.
Proceed to "CD Sound Skips"
Click here
Radio receiver or integration control & panel assembly
Illumination circuit
Click here
Steering Pad Switch Function: 
Symptom
Suspected area
See page
Audio system cannot be operated with steering pad switch.
1. Steering pad switch circuit
Click here
2. Radio receiver
Click here
Steering pad switch cannot be illuminated at night.
Illumination circuit
Click here
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