Audio System: Troubleshooting

CAUTION: When replacing the internal mechanism (computer part) of the audio system, be careful that no part of your body or clothing comes in contact with the terminals of the leads from the IC, etc. of the replacement part (spare part).

NOTE: This inspection procedure is a simple troubleshooting which 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 items into consideration:

Open or short circuit of the wire harness.

Connector or terminal connection fault.

Component/Description Of Problem/Troubleshooting Isolation Table

Component/Problem		See
Radio
Radio Not Operating When Power Switch Turned To "ON"		1
Display Indicates When Power Switch Turned To "ON," But No Sound (Including 'noise') Is Produced		2
Noise Present, But AM-FM Not Operating		3
Either Speaker Does Not Work		4
Either AM Or FM Does Not Work		5
Reception Poor		5
Few Preset Turning Bands		5
Sound Quality Poor		6
Preset Memory Disappears		7
Cannot Set Station Select Button, Preset Memory Disappears		7
Tape Player
Cassette Tape Cannot Be Inserted		8
Cassette Tape Inserts, But No Power		9
Power Coming In, But Tape Player Not Operating		10
Either Speaker Does Not Work		11
Sound Quality Poor		12
Tape Jammed, Malfunction With Tape Speed Or Auto-Reverse		13
Cassette Tape Will Not Eject.		14
Antenna
Antenna-Related		15
Noise
Noise Occurs		16
Noise Produced By Vibration Or Shock While Driving		17
Noise Produced When Engine Starts		18

The term "AM" includes LW,MW and SW, and the term "FW" includes UKW

Diagnosis function :
Error codes over tuner and connected equipment are displayed on the screen of tuner.
1. Diagnosis start-up
  For shifting to diagnosis mode, push "CD" button 3 times with pressing "1" and "6" of TRUCK TUNE APS button at the same time while the audio power is OFF and ACC is ON.
  
  Fig 1: Locating No. 1, 6, CD & Tune Up/Down Buttons
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  In diagnosis mode, by pressing "CD" button for 2 seconds or turning the ignition key OFF, the diagnosis mode is released.
2. LAN check :
  When starting up the diagnosis mode, the mode turns to LAN check mode, the screen displays the code numbers (physical address) of tuner and connected equipment. Smaller codes are displayed in order, displayed code numbers are switched by operating TUNE "UP" or TUNE "DOWN" button. In LAN check mode, by pressing "5" of TRUCK TUNE APS button for more than 2 secs., diagnosis memory of each equipment can be deleted, when deletion is completed, the mode returns to LAN check mode.
  
  Fig 2: Code Number/Physical Address Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. System check:
  When pressing "1" of TRUCK TUNE APS button in LAN check mode, the mode turns to the system check mode, the system performs self diagnosis of connected equipment and displays the results. The smaller code numbers (physical address) are displayed in order (code No. (physical address), diagnosis code, support code of diagnosis code (object equipment)). When no error is detected in the system, "00" is displayed. When an error code is detected, up to 6 codes per one system are displayed. Pressing TUNE "UP" or TUNE "DOWN" switches the display. In the system check mode, when pressing "6" of TRUCK TUNE APS button the mode returns to LAN check mode.
4. Diagnosis memory:
  In LAN check mode, when pressing "2" of TRUCK TUNE APS button the mode turns to the diagnosis memory mode. The results of self diagnosis performed over tuner and connected equipment are memorized and displayed. The smaller code numbers (physical address) are displayed in order (code No. (physical address), periodic communication number when error occurs, diagnosis code, and support code of diagnosis code (object equipment)). When no error is detected in the system, "00" is displayed. When an error code is detected, up to 6 codes per one system are displayed. Pressing TUNE "UP" or TUNE "DOWN" switches the display. Each diagnosis code is same as code in the system check mode. When pressing "6" of TRUCK TUNE APS button, the mode returns to LAN check mode.

Radio not operating when power switch turned to "ON" :

Fig 4: Not Operating When Power Switch Turned To "ON" (Radio)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Radio display indicates when power switch turned to "ON", but no sound (including "noise") is produced :

Fig 5: No Sound Produced (Radio)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Radio noise present, but AM-FM not operating :

Fig 6: Am-Fm Not Operating (Radio)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Radio either speaker does not work :

Fig 7: Speakers Not Working (Radio)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Radio either AM or FM does not work, reception poor (volume faint), few preset tuning bands :

Fig 8: Few Tuning Bands Present (Radio)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Radio cannot set station select button, preset memory disappears :

Fig 10: Preset Memory Disappears (Radio)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Tape player cassette tape cannot be inserted :

Fig 11: Cannot Insert Tape (Tape Player)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Tape player cassette tape inserts, but no power :

Fig 12: No Power W/Tape Inserted (Tape Player)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Tape player power coming in, but tape player not operating :

Fig 13: Tape Player Not Operating W/Power In (Tape Player)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Tape player either speaker does not work :

Fig 14: Either Speaker Not Working (Tape Player)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Tape player sound quality poor (volume faint)

Fig 15: Faint Volume/Poor Sound Quality (Tape Player)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Tape player tape jammed, malfunction with tape speed or auto-reverse :

Fig 16: Jammed Tape (Tape Player)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Tape player cassette tape will not eject :

Fig 17: Tape Will Not Be Eject (Tape Player)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Noise produced by vibration or shock while driving:

Fig 20: Vibration/Shock Causes Of Noise
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Noise produced when engine starts :

Fig 21: Engine Starting Causes Noise
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002