LEXUS SC400 1991 Service Repair Manual

NGOK
INSPECTION OF TRANSMITTER
HINT: Perform this inspection only when transmitter is judged to be the fault\
y in precheck type II.
1Transmitter battery capacity check.
C
OK
P
HintThis inspection is not directly for the purpose of check-
ing the capacity of the transmitter battery, but is per-
formed when remote control operation becomes difficult
or impossible, in order to ascertain if this is caused by
low battery capacity.
1. Remove the transmitter screw.
2. /Remove the cover.
3. Remove the O±ring and battery.
1. Connect 2 new 1.5 V dry±cell batteries in series.Connect the battery
terminal to the battery re-
ceptacle side terminal and the battery  terminal to
the bottom terminal to provide 3 V to the transmitter.
2. In the condition (1), push the wireless door lock re- mote control switch on the side of the transmitter
body and operate the door lock by remote control.
Remove control operation possible.
Replace the battery for transmitter (See page BE±450).
Replace transmitter and ROM in ECU
(See page BE±450).
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±447
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WIRING DIAGRAM
Check defogger wire (See page BE±173).NG
OK Repair defogger wire.
Replace antenna pinjack cable and
capacitor.1
INSPECTION OF ANTENNA CIRCUIT
Antenna Circuit
CIRCUIT DESCRIPTION
The antenna receives the electromagnetic wave emitted by the transmitter and sends i\
t to the wireless
door lock ECU.
DIAGNOSTIC CHART
HINT: Perform this inspection only when vehicle antenna is judged to be fault\
y in initial check type II.
BE±448
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
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PARTS REPLACEMENT
WIRELESS DOOR LOCK ECU REMOVAL
AND INSTALLATION
1. REMOVE WIRELESS DOOR LOCK ECU(a) Remove the rear seat.
(b) Remove the RH quarter trim panel.
(c) Disconnect the connectors.
(d) Remove the ECU.
2. INSTALL WIRELESS DOOR LOCK ECU For installation, follow the removal procedure in reverse.
WIRELESS DOOR LOCK ECU AND
TRANSMITTER REPLACEMENT
Disassembly and assembly of the wireless door lock ECU
and transmitter includes details of spare parts and replace-
ment procedure for defective parts found through trouble-
shooting.
Each part is a precision electronic component so handle with
care.
Destroy old ROM and transmitter to prevent reuse.
1. SPARE PARTS AND REPLACEMENT PROCEDURE FOR MALFUNCTIONING PARTS
(For malfunctioning transmitter)
(a) Prepare the new transmitter (with ROM).
(b) Remove the ECU from the vehicle.
(c) Remove the ROM from the ECU.
(d) Install the new ROM into the ECU.
(e) Install the ECU into the vehicle.
(f) Check that door lock remote control operation works.
(g) Cut the new key to the shape of the replaced key.
(For non±functioning battery)
(a) Prepare new battery (with O±ring).
(b) Remove battery and O±ring from transmitter.
(c) Install new battery and O±ring into transmitter.
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BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±449
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(For malfunctioning ECU)
(a) Prepare the new ECU (without ROM).
(b) Remove the ECU from the vehicle.
(c) Remove the ROM from the ECU.
(d) Install the ROM into the new ECU.
(e) Install the new ECU into the vehicle.
2. REMOVAL OF ROM FROM ECU (a) Remove the cover from the hole for ROM insertion.
(b) Using long nosed pliers, grasp the center of the print
board (ROM) and remove it.
NOTICE:
w When replacing the ROM, always disconnect the
ECU connector first.
w When removing the ROM, always grasp the board
and do not touch the IC parts or print wiring on the
board.
(c) Insert the new print board (ROM) along the rails on both sides and push it in with your finger until the terminal on
the end is completely inserted.
(d) Install the cover to the hole for ROM insertion.
3. REPLACEMENT OF BATTERY FOR TRANSMITTER (a) Remove the screw from the transmitter.
(b) Remove the cover.
BE±450
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BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
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(c) Remove the O±ring and battery.
(d) Set the new battery and O±ring into the transmitter.
(e) Install the cover to the transmitter body taking care notto twist or displace the O±ring.
(f) Tighten the screw.
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±451
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Terminals of ECU
WIRING DIAGRAM
No.SymbolTerminal NameNo.SymbolTerminal Name
W8±1+BPower SourceW8±6KSWKey Unlock Warning Switch
W8±2LSWD1Door Unlock Detection Switch LHW8±7EGround
W8±3LSWPDoor Unlock Detection Switch RHW8±8
W8±4UL1Door Key Lock and Unlock SwitchW8±9LSWD2Door Lock Motor LH
W8±5L1Door Key Lock and Unlock SwitchW8±10DSWDDoor Open Detection Switch
BE±452±
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STANDARD VALUE OF ECU TERMINAL
 

Terminals
 

Symbols
 

Wiring
color 

Condition
 

Standard
Value
 

W8±1
eW8±7
 

+B1
eE
 

R±L
eW±B
 

Wireless door lock main switch ON 

10 ~ 14 V 


W8±1eW8±7 


+B1eE 


R±LeW±B 

Wireless door lock main switch OFF
 

Below 1 V
 W8±2
eBody LSWD1 eBody L±W eBody Door lock knob of driver's door LOCK 8 ~ 10 V
 
y
Ground 
y
Ground 
y
Ground Door lock knob of driver's door UNLOCK Below 1 V
 W8±3 eBody LSWP eBody P±B eBody Door lock knob of assistant's door LOCK 8 ~ 10 V
 
y
Ground 
y
Ground 
y
Ground Door lock knob of assistant's door UNLOCK Below 1 V
 


W8 4
eBody
 


UL1
eBody
 


GW
eBody
 


Turn ignition switch ON,
Key operate switch Left and Right UNLOCK 


Below 1 V 


W8±4
eBody
Ground 


UL1
eBody
Ground 


G±W
eBody
Ground 


Turn ignition switch ON
Key operate switch Left or Right UNLOCK 


Below 1 V
    Except above mention 8 ~ 10 V
 

W8±5
eBody
 

L1
eBody
 

G±Y
eBody
 

Turn ignition switch, ON
Key operate switch Right LOCK 

Below 1 V
 


y
Ground 


y
Ground 


y
Ground 

Turn ignition switch ON,
Except above mention 

8 ~ 10 V
 W8±6
eBody KSW eBody Ye Body Ignition key insert key cylinder Below 1 V 

y
Ground 

y
Ground 

y
Ground 
Ignition key pull out key cylinder 
10 ~ 14 V 

W8±7
eBody
Ground
 

E
e Body
Ground
 

W±B
eBody
Ground
 

Always
 

Below 1 V
 

W8±9
eBody
 

LSWD2
eBody
 

W±L
eBody
 

Door lock knob of driver's door LOCK
 

8 ~ 10 V
 
y
Ground 
y
Ground 
y
Ground Door lock knob of driver's door UNLOCK Below 1 V
    Door open detection switch Left and Right ON 
 W8±10
eBody DSWD eBody G±L eBody Door open detection switch Left or Right ON Below 1 V
 
y
Ground 
y
Ground 
y
Ground Door open detection switch Left or Right OFF 
    Door open detection switch Left and Right OFF 10 ~ 14 V
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±453
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MATRIX CHART OF PROBLEM SYMPTOMS
Perform troubleshooting of the circuits for the applicable problem symptom in t\
he order given in the chart below.
Proceed to the page located for each circuit.
HINT:
w Troubleshooting of the wireless door lock control system is based on the premise that the d\
oor lock
control system is operating normally. Accordingly, before troubleshooting the wireless door lock
control system, first make certain that the door lock control system is \
operating normally.
w If the instruction ºProceed to next circuit inspection shown on matrix \
chartº is given in the flow chart for each
circuit, proceed to the circuit with the next highest number in the table to con\
tinue the check.
w If the trouble still reappears even though there are no abnormalities in a\
ny of the other circuits, then check
and replace the Wireless Door Lock ECU as the last step.
See page
BE±460BE±462BE±464BE±466BE±468BE±470IN±32
SymptomSuspect
Area
ECU Power Source CircuitDoor Unlock Detection Switch CircuitDoor Key Lock and Unlock Swtich Circuit
(Unlock Side)Door Key Lock and Unlock Swtich Circuit
(Lock Side)Key Unlock Warning Switch CircuitDoor Open Detection Swtich CircuitWireless Door Lock ECU
All functions of wireless door lock control system do not
operate.134526
Only door unlock operation is not possible
(Lock operation is possible).213
Only door lock operation is not possible
(Unlock operation is possible).12
Only transmitter misoperation prevention function is not
possible12
Wireless door lock function operates even when each door is
opened.12
Wireless door lock functions incorrectly.
(Although one door is unlocked, when the transmitter switch
is pressed, all doors unlock.)
12
BE±454±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
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±MEMO±
±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control SystemBE±455
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LOCATION OF CONNECTORS
Location of Connectors in Engine Compartment
BE±456±
BODY ELECTRICAL SYSTEM Wireless Door Lock Control System
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