Page 225 of 1807
Z18233
Seat Heater Relay (for Driver's)
Seat Heater Relay (for Passenger's) Seat Heater Switch
SEAT-HTR Fuse
(Seat Cushion) Seat Heater
Seat Heater
(Seat Back) J/B No.1
BE0EK-01
- BODY ELECTRICALSEAT HEATER SYSTEM
BE-69
2047 Author: Date:
1997 SUPRA (RM502U)
SEAT HEATER SYSTEM
LOCATION
Page 226 of 1807

BE0EL-01
Z09260
N08884
Z09261
Connector ºAº
Connector ºBº BE-70
- BODY ELECTRICALSEAT HEATER SYSTEM
2048 Author: Date:
1997 SUPRA (RM502U)
INSPECTION
1. INSPECT SEAT HEATER SWITCH CONTINUITY
ConditionTester connectionSpecified condition
SW ON (LEFT)2 - 4Continuity
SW ON (RIGHT)4 - 6Continuity
SW OFF -No continuity
Illumination circuit3 - 5Continuity
If continuity is not as specified, replace the switch or bulb.
2. INSPECT SEAT HEATER SWITCH INDICATOR
(a) Connect the positive (+) lead from the battery to terminal
2 and 6 and the negative (-) lead to terminal 1.
(b) Push the switches, check that the indicator lights up.
If operation is not as specified, replace the switch and inspect
the circuits connected to other parts.
3. INSPECT SEAT CUSHION CONTINUITY
(a) Heat the thermostat with a light.
(b) Inspect the seat heater continuity between terminals.
Tester connectionConditionSpecified condition
A1 - A2ConstantContinuity
A1 - B2ConstantContinuity
A2 - B2ConstantContinuity
A3 - A4Seat heater temperature
below 25°C (77°F)Continuity
A4 - B1Seat heater temperature
below 25°C (77°F)Continuity
A3 - A4Seat heater temperature
above 45°C (113°F)No Continuity
A4 - B1Seat heater temperature
above 45°C (113°F)No Continuity
If continuity is not as specified, replace the seat cushion pad.
Page 227 of 1807
Z09262
Seat Back Side
Z09263
- BODY ELECTRICALSEAT HEATER SYSTEM
BE-71
2049 Author: Date:
1997 SUPRA (RM502U)
4. INSPECT SEAT BACK CONTINUITY
Inspect the seat heater continuity between terminals, as
shown.
Tester connectionConditionSpecified condition
1 - 3ConstantContinuity
2 - 4ConstantContinuity
If continuity is not as specified, replace the seat back pad.
5. INSPECT SEAT HEATER RELAY CONTINUITY
ConditionTester connectionSpecified condition
Constant1 - 3Continuity
Apply B+ between
terminals 1 and 3.2 - 4Continuity
If continuity is not as specified, replace the relay.
Page 228 of 1807

BE0EM-01
The radio wave bands used in radio broadcasting are as follows:
Frequency
Designation
Radio wave
Modulation method
LF: Low frequency MF: Medium Frequency HF: High Frequency VHF: Very High FrequencyAmplitude modulationFrequency modulation 30 kHz
300 kHz3 MHz 30 MHz 300 MHz
LF
MFHFVHF
AM FM
BE2818
FM (Stereo)
FM (Monaural)
AM
BE2819
FadingIonosphere BE-72
- BODY ELECTRICALAUDIO SYSTEM
2050 Author: Date:
1997 SUPRA (RM502U)
AUDIO SYSTEM
DESCRIPTION
1. RADIO WAVE BAND
2. SERVICE AREA
There are great differences in the size of the service area for AM
and FM monaural. Sometimes FM stereo broadcasts cannot be
received even through AM can be received in very clearly.
Not only does FM stereo have the smallest service area, but it
also picks up static and other types of interference (ºnoiseº)
easily.
3. RECEPTION PROBLEMS
Besides the problem of static, there are also the problems
called ºfadingº, ºmultipathº and ºfade outº. These problems are
caused not by electrical noise but by the nature of the radio
waves themselves.
(a) Fading
Besides electrical interference, AM broadcasts are also
susceptible to other types of interference, especially at
night. This is because AM radio waves bounce off the ion-
osphere at night. These radio waves then interfere with
the signals from the same transmitter that reach the ve-
hicle's antenna directly. This type of interference is called
ºfadingº.
Page 229 of 1807

BE2820
Multipath
BE2821
Fade Out
N17398
Example :
HeadCapstan
Pinch Roller
- BODY ELECTRICALAUDIO SYSTEM
BE-73
2051 Author: Date:
1997 SUPRA (RM502U)
(b) Multipath
One type of interference caused by the bounce of radio
waves off of obstructions is called ºmultipathº. Multipath
occurs when a signal from the broadcast transmitter an-
tenna bounces off buildings and mountains and interferes
with the signal that is received directly.
(c) Fade Out
Because FM radio waves are of higher frequencies than
AM radio waves, they bounce off buildings, mountains,
and other obstructions. For this reason, FM signals often
seem to gradually disappear or fade away as the vehicle
goes behind a building or other obstruction. This is called
ºfade outº.
4. COMPACT DISC PLAYER
Compact Disc (hereafter called ºCDº) Players use a laser beam
pick-up to read the digital signals recorded on the CD and re-
produce analog signals of the music, etc. There are 4.7 in. (12
cm) and 3.2 in. (8 cm) discs in the CD player.
HINT:
Never attempt to disassemble or oil any part of the player unit.
Do not insert any object other than a disc into the magazine.
NOTICE:
CD players use an invisible laser beam which could cause
hazardous radiation exposure. Be sure to operate the play-
er correctly as instructed.
5. Tape Player/Head Cleaning:
MAINTENANCE
(a) Raise the cassette door with your finger.
Next, using a pencil or similar object, push in the guide.
(b) Using a cleaning pen or cotton applicator soaked in clean-
er, clean the head surface, pinch rollers and capstans.
Page 230 of 1807

BE4331
BE2826
Cassette Tape Slot Cover BE-74
- BODY ELECTRICALAUDIO SYSTEM
2052 Author: Date:
1997 SUPRA (RM502U)
6. CD Player/Disc Cleaning:
MAINTENANCE
If the disc gets dirty, clean the disc by wiping the surface from
the center to outside in the radial directions with a soft cloth.
NOTICE:
Do not use a conventional record cleaner or anti-static pre-
servative.
7. ANTI-THEFT SYSTEM
HINT:
The words ºANTI-THEFT SYSTEMº are displayed on the cas-
sette tape slot cover.
For operation instructions for the anti-theft system, please con-
sult the audio system section in the Owner's Manual (hereafter
called O/M).
(a) Setting system
The system is in operation once the customer has pushed
the required buttons and entered the customer-selected
3-digit ID number.
(Refer to the O/M section, ºSetting the anti-theft systemº)
HINT:
When the audio system is shipped, the ID number has not
been input, so the anti-theft system is not in operation.
If the ID number has not been input, the audio system re-
mains the same as a normal audio system.
(b) Anti-theft system operation
If the normal electrical power source (Connector or bat-
tery terminal) is cut off, the audio system becomes inoper-
able, even if the power supply resumes.
(c) Canceling system
The ID number chosen by the customer is input to cancel
the anti-theft system
(Refer to the O/M section, ºIf the system is activatedº)
HINT:
To change or cancel the ID number, please refer to the O/M
ºCancelling the systemº.
Page 231 of 1807

BE0EN-01
- BODY ELECTRICALAUDIO SYSTEM
BE-75
2053 Author: Date:
1997 SUPRA (RM502U)
TROUBLESHOOTING
NOTICE:
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 re-
placement part (spare part).
HINT:
This inspection procedure is a simple troubleshooting which should be carried out on the vehicle during sys-
tem 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
For audio systems with anti-theft system, troubleshooting items marked ( * ) indicate that ºTrou-
bleshooting for ANTI-THEFT SYSTEMº should be carried out first.
ProblemNo.
RadioRadio 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
Any speaker does not work.4
Any AM or FM does not work.5
Few preset turning bands.5
Reception poor.6
Sound quality poor.7
Preset memory disappears.8
Tape PlayerCassette tape cannot be inserted.9
Cassette tape inserts, but no power.10
Power coming in, but tape player not operating.11
Any speaker does not work.12
Sound quality poor.13
Tape jammed, malfunction with tape speed or auto-reverse.14
Cassette tape will not eject.15
CD PlayerCD cannot be inserted.16
CD inserted, but no power.17
Power coming in, but CD player not operating.18
Sound jumps.19
Sound quality poor (Volume faint).20
Any speaker does not work.21
CD will not be ejected.22
Power AmplifierNo power coming in.23
Power coming in, but power amplifier not operating.24
Any speaker does not work.25
AntennaAntenna does not fully extend or fully retract.26
Antenna - related.27
NoiseNoise produced by vibration or shock while driving.28
Noise produced when engine starts.29
The term ºAMº includes LW,MW and SW, and the term ºFWº includes UKW.
Page 232 of 1807

V08418
Turn ignition Key from LOCK position to ACC position.
Troubleshooting for ANTI-THEFT SYSTEM
Display A:
ID Number is set.Display E:
ANTI-THEFT SYSTEM opera-
tion condition. (ID number input
error 10 times or more.)Display B
ºSEC display disappears after 1
second.Radio switch ON.
Take to designated radio
service station.Display BDisplay D
Refer to each
malfunction item.Normal
operation.
Radio switch ON. Normal operation.
Cancel ID number, refer to each malfunction item.
Ye s
No
OK
NG
ANTI-THEFT SYSTEM operation condition. (ID number input error 9 times or less.)
Input ID number to cancel ANTI-THEFT SYSTEM, and check display.
Display A"B Display B Display E
Display C"A
Radio switch ON.Refer to each
malfunction item.Take to designated
radio service station.ANTI-THEFT SYSTEM not can-
celled. (ID number input error 10
times or less.)
Display D
ANTI-THEFT SYSTEM cancelled.
Check audio system again.Normal operation.
OK
NG
Cancel ID number, refer to each malfunction item.
Liquid Crystal Display (LCD) or VFD for Audio System
Display ºAº Display ºBº Display ºCº
Display ºDº Example:Display ºEº
2 DIN Type
1 DIN TypeBlank
No Illumination
2 DIN Type
1 DIN Type 2 DIN Type
1 DIN Type Error Times2 DIN Type 1 DIN Type
Radio Display
1 DIN Type 2 DIN Type
HINT:
Refer to Owner's Manual for operation details of ANTI-THEFT SYSTEM.
When the ID number has been cancelled, reset the same number after completing the operation, or
inform the customer that it has been cancelled.
BE-76
- BODY ELECTRICALAUDIO SYSTEM
2054 Author: Date:
1997 SUPRA (RM502U)