1995 TOYOTA SUPRA warning

LIGHT FAILURE SENSOR INSPECTION
1. INSPECT SENSOR CIRCUIT
Disconnect the connector from the sensor and inspect the
connector on the wire harness side, as shown.
 
 
 
Tester connection to
terminal number
 
 
 
Condition
 
 
 
Specified condition
 1±Ground Constant Continuity*
 2±Ground Constant Continuity*
 9±Ground Constant Continuity* 
 10±Ground
 
 Constant
 
 Continuity*
 11±Ground Constant Continuity
 12±Ground Constant Continuity*
 3±Ground Light control switch position OFF No Voltage 3±Ground Light control switch position TAIL or HEAD Battery positive voltage 
 4±Ground
 
 Ignition switch position LOCK or ACC
 
 No voltage
 4±Ground Ignition switch position ON Battery positive voltage
 7±Ground Stop light switch position OFF No voltage
 7±Ground Stop light switch position ON Battery positive voltage 
 8±Ground
 
 Engine condition Stop
 
 No voltage
 8±Ground Engine condition Running Battery positive voltage
*: There is resistance because this circuit is grounded
through the bulb.
If circuit is as specified, replace the sensor.
If the circuit is not as specified, inspect the circuits connected
to other parts.
2. INSPECT WARNING LIGHT
(a) Disconnect the connector from the light failure sensor and
ground terminal 4 on the wire harness side connector.
(b) Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or inspect
wire harness.
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±53

OPEN DOOR WARNING INSPECTION
1. INSPECT DOOR COURTESY SWITCH
 
 Switch Position
 
 
Tester connection to
terminal number 
 Specified condition
 
 ON
(Switch pin released) 
 1±2
2±3 
 Continuity
 
 OFF
(Switch pin pushed in) 
 ±
 
 No continuity
If continuity is not as specified, replace the switch.
2. INSPECT WARNING LIGHT
Disconnect the connector from the door courtesy switch, and
ground terminal 1 on the wire harness side connector and
check that the warning light lights up.
If the warning light does not light up, inspect the bulb or wire
harness.
LIGHT CONTROL RHEOSTAT
INSPECTION
INSPECT LIGHT CONTROL RHEOSTAT
(a) Connect the positive (+) lead from the battery to terminal 1
and negative lead (±) to terminal 3.
(b) Connect the positive (+) lead from the voltmeter to terminal
2 and negative lead to terminal 3.
(c) Turn the rheostat knob and check that the voltage changes. BE±54
± BODY ELECTRICAL SYSTEMCOMBINATION METER

SEAT BELT WARNING INSPECTION
1. INSPECT INTEGRATION RELAY OPERATION
(a) Connect the positive (+) lead from the battery to terminals 1
and 7.
(b) Connect the positive (+) lead from the battery to terminal 9
through a 3.4W test bulb.
(c) Check that the test bulb lights up and buzzer sounds for 4±8
seconds when the negative (±) lead from the battery is
connected to terminal 10.
(d) Check that the buzzer sounding in (c) stops when the
negative (±) lead from the battery is connected to terminal 8.
If operation is not as specified, replace the integration relay.
2. INSPECT RELAY CIRCUIT
Remove the relay from the junction block No.1 and inspect
the connectors on the junction block side.
 
 Tester connection to
terminal number 
 Condition
 
 Specified condition
 4±Ground Driver's door open Continuity 
 4±Ground
 
 Driver's door close
 
 No continuity
 5±Ground Ignition key Set Continuity
 5±Ground Ignition key remove No continuity
 8±Ground Driver's seat belt fasten Continuity 
 8±Ground
 
 Driver's seat belt unfasten
 
 No continuity
 10±Ground Constant Continuity
 1±Ground Constant Battery positive voltage
 9±Ground Ignition switch position ON Battery positive voltage 
 9±Ground
 
 Ignition switch position LOCK or ACC
 
 No voltage
If circuit is not as specified, try replacing the relay with a new
one.
± BODY ELECTRICAL SYSTEMCOMBINATION METERBE±55

MATRIX CHART OF PROBLEM SYMPTOMS
Proceed to the reference page shown in the matrix chart below for each malfunction symptom and troubleshoot
for each circuit.
HINT: Troubleshooting of the theft deterrent system is based on the premise that the door lock control system
is operating normally. Accordingly, before troubleshooting the theft deterrent system, first make certain that the
door lock control system is operating normally.
Theft Deterrent System
 Details of Problem Inspecting Circuit *1 See Page
  1. Indicator light circuit BE±128
 
 
Th th ft d t t t t b t
 
 2. Luggage compartment door key
lock and unlock switch circuit 
 BE±142
 The theft deterrent system cannot be set 3. Luggage Room Light switch circuit BE±144 
 
 
 4. Door courtesy switch circuit
 
 BE±147
  5. Engine hood courtesy switch circuit BE±148
 The indicator light does not blink when system is set Indicator light circuit BE±128
 
 
 When the
system is
 
 
 
When the back door is
opened by a method other
than the key. 
 
 The system
does not
 
 
 
Luggage compartment door courtesy
switch circuit
 
 
 BE±144
 
 
system is
set 
 When the engine hood is
opened 
 
does not
Operate 
 Engine hood courtesy switch circuit
 
 BE±148
 
 
 
 Horns do not sound 
 Horn relay circuit 
 BE±132
 
 While the system
ii i
 
 
Theft deterrent horn does not
sound 
 
Theft deterrent horn circuit 
 
BE±134
 is in warning
operation Headlights do not flash Headlight control relay circuit BE±136
 o eration Taillights do not flash Taillight control relay circuit BE±138
  The starter cut is not cut off Starter relay circuit BE±130 
 
 When the
System is
 
 
 
It is not cancelled when the
ignition key is Turned to ACC
or ON position
 
 
 Ignition switch circuit
 
 
 BE±140
 
 
 
System is
Set 
 
 
It still operates when the back
door is Opened with the key
 
 
 
Luggage compartment door key lock
and unlock switch circuit
 
 
 
BE±142
 System is still set even when a rear door is open Door courtesy switch circuit BE±147
  Horns sound Horn relay circuit BE±132
 Even when the Theft deterrent horn sounds Theft deterrent horn circuit BE±134
 

Even when the
System is not set 
Headlights stay on 
Headlight control relay circuit 
BE±136 
 
 
 Taillights stay on
 
 Taillight control relay circuit
 
 BE±138
*1
: If numbers are given to the circuit proceed with troubleshooting in the order indicated by those numbers.
± BODY ELECTRICAL SYSTEMBE±123THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

Door Lock System
 Trouble Suspect Area See Page
 
 
 
 
Whole function of the door lock control system
does not operate.
 
 
 
 
1. ECU Power Source Circuit
2. Actuator Power Source Circuit
3. Door Lock Motor Circuit
4. Theft Deterrent and Door Lock Control ECU 
 
 
 
BE±150
BE±152
BE±154
BE±125
 
 
 
 
All doors or some doors are not locked and un-
locked with the door lock control switch and
Key lock and unlock switch. 
 
 
 
1. Door Lock Control Switch Circuit
2. Door Key Lock and Unlock Switch Circuit
3. Door Lock Motor Circuit
4. Theft Deterrent and Door Lock Control ECU 
 
 
 
BE±156
BE±158
BE±154
BE±125
 
 
 
Doors cannot be locked with the door lock con-
trol switch. (Doors lock and unlock normally
With the key lock and unlock switch.) 
 
 
1. Door Lock Control Switch Circuit
2. Key Unlock Warning Switch Circuit
3. Door Courtesy Switch Circuit
4. Theft Deterrent and Door Lock Control ECU 
 
 
BE±156
BE±160
BE±147
BE±125
 
 
 
Doors are not locked or unlocked with the door
key Lock and unlock switch. (Doors lock and un-
lock normally with the door lock control switch.)
 
 
 
1. Door Key Lock and Unlock Switch Circuit
2. Theft Deterrent and Door Lock Control ECU
 
 
 BE±158
BE±125
 
 
 
Key confinement prevention function does not
Operate. (Doors lock and unlock normally with
The door key lock and unlock switch.)
 
 
 
1. Key Unlock Warning Switch Circuit
2. Door Unlock Detection Switch Circuit
3. Theft Deterrent and Door Lock Control ECU
 
 
 
BE±160
BE±145
BE±125
BE±124± BODY ELECTRICAL SYSTEM
THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

TERMINALS OF ECU
 No. Symbol Terminal Name No. Symbol Terminal Name
 T8±1 +B2 Power Source T9±1 +B1 Power Source
 T8±2 ACT± Door Lock Motor T9±2 ± ± 
 T8±3
 
 ACT+
 
 Door Lock Motor
 
 T9±3
 
 ±
 
 ±
 T8±4 E Ground 
T9 4
 
DSWL
 Luggage Compartment Door Courtesy
 T8±5 ± ± T9±4 DSWL 
Luggage Com artment Door Courtesy
Switch
 T8±6 RLY Power Main Relay T9±5 L1 Door Lock Control Switch (Lock) 
 T8±7
 
 IG
 
 Ignition Switch ºONº
 
 T9±6
 
 UL3
 
 Door Key Lock and Unlock Switch
 T8±8 ACC Ignition Switch ºACCº T9±7 DSWD Door Open Detection Switch
 T8±9 ± ± T9±8 UL1 Door Lock Control Switch (Unlock)
 
T9 9
 
LUG
 Luggage Compartment Door Key Lock T9±9 LUG Luggage Com artment Door Key Lock
and Unlock Switch
 T9±10 HEAD Headlight Control Relay 
 T9±11
 
 SH
 
 Theft Deterrent Horn
 T9±12 IND Security Indicator Light
 T9±13 ± ±
 T9±14 FOD Engine Hood Courtesy Switch  
LSWD
 
Door Unlock Detection Switch or Door T9±15 LSWD,
UL2 Door Unlock Detection Switch or Door
K L k d U l k S it h
T9±15
UL2Key Lock and Unlock Switch 
 T9±16
 
 ±
 
 ±
 T9±17 ± ±
 T9±18 ± ±
 T9±19 DSWP Door Open Detection Switch 
 T9±20
 
 KSW
 
 Key Unlock Warning Switch
 T9±21 LSWP Door Unlock Detection Switch
 T9±22 L2 Door Key Lock and Unlock Switch
 T9±23 TAIL Taillight Control Relay 
 T9±24
 
 HORN
 
 HORN Relay
 T9±25 SRLY Ignition Switch ºSTº
± BODY ELECTRICAL SYSTEMBE±125THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

 Terminals Symbols Condition Standard Value
 
 
T9±12±Ground
(IND±Ground) 
 W±L±Ground
 
 Always
 
 Below 270

 T9±14±T8±4 
VR WB
 Engine hood courtesy switch ON (hood opened). Below 1
 
 
T9 14 T8 4
(FOD±E) 
 
VR±WB 
 Engine hood courtesy switch OFF (hood closed). 
 1 M
or higher
 T9±15±T8±4 LW W B Door unlock detection switch ON (door opened). Below 1

 
T9 15 T8 4
(LSWD±E) LW±WB Door unlock detection switch OFF (door closed). 1 M
or higher
 
T9 15 T8 4
  Door key lock and unlock switch ºunlockº position Below 1
 
 
T9±15±T8±4
(UL2±E) 
 W±WB 
 Door key lock and unlock switch OFF or ºlockº
position 
 1 M
or higher
   
Door open detection switch (passenger's) ON
 
Below 1
 
 T9±19±T8±4
 
 RL WB
 
 
Door oen detection switch ( assenger s) ON
(door opened). 
 
Below 1

 
T9 19 T8 4
(DSWP±E) 
RL±WB
 Door open detection switch (passenger's) OFF 1M
or higher
   
Door oen detection switch ( assenger s) OFF
(door closed). 
1 M
or higher
 T9±20±T8±4 
YWB
 Key unlock warning switch ON. Below 1

 
T9 20 T8 4
(KSW±E) Y±WB Key unlock warning switch OFF. 1 M
or higher
 
T9±21±T8±4
 
GB WB
 Door unlock detection switch ON (door opened). Below 1
 
 
T9 21 T8 4
(LSWP±E) 
 
GB±WB 
 Door unlock detection switch OFF (door closed).
 
 1 M
or higher
 
T9 22 T8 4
  Door key lock and unlock switch ºlockº position. Below 1

 
 
T9±22±T8±4
(L2±E) 
 
GY±WB 
 
Door key lock and unlock switch OFF or ºunlockº
position. 
 1 M
or higher
 
 T9±23±T8±4
(TAIL±E) 
 GW±WB
 
 Light control switch ºTAILº position.
 
 10±14 V
 
 T9±24±T8±4
(HORN±E) 
 LR±WB
 
 Horn switch OFF.
 
 10±14 V
 
 T9±25±Ground
(SRLY±Ground) 
 L±O±Ground
 
 Ignition switch is turned to ºSTº position.
(When park / neutral position switch ºPº position) 
 10±14 V
± BODY ELECTRICAL SYSTEMBE±127THEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM

Ignition Switch Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned to the ACC position, battery positive voltage is applied to the terminal ACC
of the ECU. Also, if the ignition switch is turned to the ON position, battery voltage is applied to the terminals
ACC and IG of the ECU. When the battery positive voltage is applied to the terminal ACC of the ECU while the
theft deterrent system is activated, the warning stops. Furthermore, power supplied from the terminals ACC and
IG of the ECU is used as power for the door courtesy switch, and position switch, etc.
BE±140± BODY ELECTRICAL SYSTEMTHEFT DETERRENT AND DOOR LOCK CONTROL SYSTEM