1995 TOYOTA SUPRA ignition

PRECAUTION
Take care to observe the doing precautions when performing inspections or removal and replacement of
body electrical related parts.
HEADLIGHT SYSTEM
wHalogen bulbs have pressurized gas inside and require special handling. They can burst if scratched or
dropped. Hold a bulb only by its plastic or metal case.
Don't touch the glass part of a bulb with bare hands.
SRS (SUPPLEMENTAL RESTRAINT SYSTEM)
wWork must be started after 90 seconds from the time the ignition switch is turned to the ºLOCKº position
and the negative (±) terminal cable is disconnected from the battery.
wWhen disconnecting any of the connectors in the SRS, be sure to lock the ignition switch and disconnect
the negative (±) terminal cable from the battery first. Since the connectors are twin lock type connectors,
disconnect the connectors only after releasing the first stage lock.
wWhen connecting SRS connectors, be sure to lock them securely. (If the connectors are not locked
securely, the system may not operate when needed.)
wAlways store the steering wheel pad with the pad surface facing upward. (Storing the pad with its metallic
surface up may lead to a serious accident if the SRS inflates for some reason.)
wWhen installing the spiral cable, be sure the vehicle is in the straight ahead condition and confirm that the
spiral cable is in the neutral position when it is installed.
wINFORMATION LABELS (NOTICE) are attached to the periphery of the SRS components. Follow the
NOTICE.
AUDIO SYSTEM
wIf the negative (±) terminal cable is disconnected from the battery, the preset AM, FM 1 and FM 2 stations
stored in memory are erased, so be sure to note the stations and reset them after the battery terminal is
reconnected.
wIf the negative (±) terminal cable is disconnected from the battery, the ºANTI±THEFT SYSTEMº will operate
when the cable is reconnected, but the radio, tape player and CD player will not operate. Be sure to input
the correct ID number so that the radio, tape player and CD player can be operated again.
MOBILE COMMUNICATION SYSTEM
wIf the vehicle is equipped with a mobile communication system, refer to precautions in the IN section. BE±2
± BODY ELECTRICAL SYSTEMPRECAUTION

PARTS LOCATION
IGNITION SWITCH INSPECTION
INSPECT SWITCH CONTINUITY
Switch position
4 ± 5 ± 7
2 ± 3
Tester connection to
terminal numberSpecified condition
5 ± 7ACC
Lock
ON
No continuity
START
Continuity
±
Continuity
Continuity4 ± 7 ± 8
1 ± 2 ± 3
If continuity is not as specified, replace the switch
IGNITION SWITCH
BE±8± BODY ELECTRICAL SYSTEMIGNITION SWITCH

KEY UNLOCK WARNING INSPECTION
1. INSPECT INTEGRATION RELAY OPERATION
(a) Connect the positive (+) lead from the battery to terminal 1,
the negative (±) lead to terminals 5 and 10.
(b) Check that the buzzer sounds when the negative (±) lead
from the battery is connected to terminal 6.
If operation is not as specified, replace the relay.
2. INSPECT RELAY CIRCUIT
See page BE±18
± BODY ELECTRICAL SYSTEMIGNITION SWITCHBE±9

INTEGRATION RELAY INSPECTION
INSPECT RELAY CIRCUIT
Light Auto Turn Off System
Remove the relay from junction block and inspect the con-
nectors on the wire harness and junction block side, as
shown in the chart.
 
 
Tester connection to
terminal number 
 Condition 
 Specified condition
 A6±Ground  Driver's door courtesy switch OFF No continuity
 A6±Ground Driver's door courtesy switch ON Continuity
 A10±Ground Constant Continuity
 B1±Ground Light control switch position OFF or TAIL No continuity
 B1±Ground Light control switch position HEAD Continuity
 B4±Ground Light control switch position OFF No continuity B4±Ground Light control switch position TAIL or HEAD Continuity A1±Ground Constant Battery positive voltage 
 A7±Ground
 
 Ignition switch position LOCK or ACC
 
 No voltage
 A7±Ground Ignition switch position ON Battery positive voltage
 B2±Ground Constant Battery positive voltage
 B3±Ground Constant Battery positive voltage
If the circuit is as specified, try replacing the relay with a new
one.
If the circuit is not as specified, inspect the circuits connected
to other parts.
DOOR COURTESY SWITCH INSPECTION
See page BE±28
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEMBE±17

DAYTIME RUNNING LIGHT MAIN RELAY
INSPECTION
INSPECT RELAY CIRCUIT
Disconnect the connector from relay and inspect the connec-
tor on wire harness side, as shown.
 
 Tester connection to
terminal number 
 Condition
 
 Specified condition
 
 5±Ground
 
 Headlight dimmer switch position Low
beam or high beam 
  No continuity
 5±Ground  Headlight dimmer switch position Flash Continuity 8±Ground Parking brake switch position OFF No continuity 8±Ground Parking brake switch position ON Continuity 
16±Ground
 
Headlight dimmer switch position Low beam
 
No continuity
 16±Ground Headlight dimmer switch position Flash or
High beam Continuity
 
 13±Ground
 
 Constant
 
 Continuity
 18±Ground Constant Continuity
 2±Ground Ignition switch position LOCK or ACC No voltage
 2±Ground Ignition switch position ON Battery positive voltage
 11±Ground Engine Stop No voltage
 11±Ground Engine Running Battery positive voltage
 15±Ground  
15±Ground
17 GroundConstantBattery positive voltage 17±Ground Constant Battery ositive voltage
If the circuit is as specified, trying replacing the relay with a
new one. If the circuit is not as specified, inspect the circuit
connected to other parts.
PARKING BRAKE SWITCH INSPECTION
See page BE±52 BE±18
± BODY ELECTRICAL SYSTEMHEADLIGHT AND TAILLIGHT SYSTEM

TROUBLESHOOTING
The table below will be useful for you in troubleshooting these electrical problems. The most likely causes
of the malfunction are shown in the order of their probability. Inspect each part in the order shown, and
replace the part when it is found to be faulty.
 Trouble Parts name (See page)
 
 
 
ºHazardº and ºTurnº do not light up
 
 
 
1. Hazard Warning Switch (BE±22)
2. Turn Signal Flasher (BE±22)
3. Wire Harness
 
 
 
The flashing frequency is abnormal
 
 
 
1. Bulb
2. Turn Signal Flasher (BE±22)
3. Wire Harness
 Hazard warning light does not light up
(Turn is normal) 1. HAZ±HORN Fuse (BE±5)
2. Wire Harness
 
 Hazard warning light does not light up in one direction
 
 1. Hazard Warning Switch (BE±22)
2. Wire Harness
 
 
 
 
*1 Turn signal does not light up
 
 
 
 
1. Ignition Switch (BE±8)
2. TURN Fuse (BE±6)
3. Turn Signal Switch (BE±21)
4. Wire Harness
 
 
 
*2 Turn signal does not light up
 
 
 
1. TURN Fuse (BE±6)
2. Turn Signal Switch (BE±21)
3. Wire Harness
 
 Turn signal does not light up in one direction
 
 
1. Turn Signal Switch (BE±21)
2. Wire Harness
 
 Only one bulb does not light up
 
 
1. Bulb
2. Wire Harness
*1: Combination Meter, Wiper and Washer do not operate.
*
2: Combination Meter, Wiper and Washer are normal.
TURN SIGNAL SWITCH INSPECTION
INSPECT SWITCH CONTINUITY 
 Switch position
 
 Tester connection to
terminal number
 
 Specified condition
 
 Left turn
 
 A1 ± A5
 
 Continuity 
 Neutral
 
 ±
 
 No continuity
 Right turn A1 ± A8 Continuity
If continuity is not as specified, replace the switch.
± BODY ELECTRICAL SYSTEMTURN SIGNAL AND HAZARD WARNING SYSTEMBE±21

INTEGRATION RELAY INSPECTION
INSPECT RELAY CIRCUIT
Remove the relay from junction block and inspect the con-
nector on the junction block side, as shown in the chart.
 
 Tester connection to
terminal number 
 Condition
 
 Specified condition
 4±Ground Courtesy Switch Position OFF (Door closed) No continuity 
 4±Ground
 
 Courtesy Switch Position ON (Door opened)
 
 Continuity
 10±Ground Constant Continuity
 1±Ground Constant Battery positive voltage
 7±Ground Ignition switch position / LOCK or ACC No voltage 
 7±Ground
 
 Ignition switch position / ON
 
 Battery positive voltage
If circuit is as specified, trying replacing the relay with a new
one.
If the circuit is not as specified, inspect the circuits connected
to other parts.
DOOR KEY LOCK AND UNLOCK
SWITCH INSPECTION
See page BE±158
DOOR UNLOCK DETECTION SWITCH
INSPECTION
See page BE±145
± BODY ELECTRICAL SYSTEMINTERIOR LIGHT SYSTEMBE±29

TROUBLESHOOTING
The table below will be useful for you in troubleshooting these electrical problems. The most likely causes
of the malfunction are shown in the order of their probability. Inspect each part in the order shown, and
replace the part when it is found to be faulty.
 
 Trouble
 
 Parts name (See page)
 
 
 
 
 
Back Up Light does not light up
 
 
 
 
 
1. GAUGE Fuse (BE±6)
2. Ignition Switch (BE±8)
3. Back±up Light Switch (M/T) (BE±31)
4. Park/ Neutral Position Switch (A/T) (AT1±Section)
5. Wire Harness
6. Bulb
 Back Up Light remains always on 1. Wire Harness 
 

Only one light does not light up
 
 

1. Wire Harness
2. Bulb
BACK UP LIGHT SWITCH INSPECTION
INSPECT SWITCH CONTINUITY 
 
 
Switch position
 
 
 
Tester connection to
terminal number
 
 
 
Specified condition
 Free 1±2 No continuity
 Push 1±2 Continuity
If continuity is not as specified, replace the switch.
PARK/NEUTRAL POSITION SWITCH
INSPECTION
See AT section
± BODY ELECTRICAL SYSTEMBACK±UP LIGHT SYSTEMBE±31