2003 LEXUS LS430 lock

Theft warning ECU assy:
DATA LIST - THEFT WARNING ECU ASSY
2.ACTIVE TEST
HINT:
Performing the hand-held tester's ACTIVE TEST allows relay, VSV, actuator and other items to be
operated without removing any parts. Performing the ACTIVE TEST early in troubleshooting is one way
to save time. The DATA LIST can be displayed during the ACTIVE TEST.
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON.
c. Perform the ACTIVE TEST by following the directions on the tester screen.
Steering lock ECU:
ACTIVE TEST - STEERING LOCK ECU
DIAGNOSTIC TROUBLE CODE CHART
sub-key/min. 0, max. 15sub-key
REGIST MAS CODENumber of registered
master key/min. 0, max.
15Number of registered
master key-
REG CODE SPACEMemory space for key
codes registration/ NOT
FULL or FULLNOT FUL: Possible to
register more key codes
FULL: Cannot register
any more key codes-
Item
Measurement Item/
Display (Range)
Normal ConditionDiagnostic Note
ACC SWIgnition switch signal/ON
or OFFOFF: Ignition switch is
OFF ON: Ignition switch
is ACC-
IG SWIgnition switch signal/ON
or OFFOFF: Ignition switch is
OFF or ACC ON:
Ignition switch is ON-
ItemTester DetailsDiagnostic Note
SECURITY INDICTurn security indicator ON/OFF-
DTCDescription
DTC B2780PUSH SWITCH/KEY UNLOCK WARNING
SWITCH MALFUNCTION

1.STEERING LOCK ECU DTC CHART
Fig. 27: Steering Lock ECU DTC Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
2.ECM DTC CHART
Fig. 28: ECM DTC Chart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
DTC B2793TRANSPONDER CHIP MALFUNCTION
DTC B2794UNMATCHED ENCRYPTION CODE
DTC B2795UNMATCHED KEY CODE
DTC B2797COMMUNICATION MALFUNCTION NO.1
DTC B2799ENGINE IMMOBILIZER SYSTEM
MALFUNCTION

CIRCUIT DESCRIPTION
This DTC will be output if the steering lock ECU does not detect that the unlock warning switch is ON even
when the ignition switch is ON. Under the normal conditions, the unlock warning switch is ON when the
ignition switch is ON.
Fig. 29: Push Switch/Key Unlock Warning Switch Malfunction Circuit Description

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
WIRING DIAGRAM
Fig. 30: Push Switch/Key Unlock Warning Switch Malfunction
- Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.READ DATA LIST USING HAND-HELD TESTER
a. Connect the hand-held tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
b. Turn the ignition switch ON with the key that cannot start the engine.
c. Read the DATA LIST.
Steering lock ECU:
DATA LIST - STEERING LOCK ECU
Measurement Item/

OK: "ON" (Key is in ignition key cylinder) appears on the screen.
NG: Go to step 2
OK: REPLACE STEERING LOCK ECU
2.INSPECT UNLOCK WARNING SWITCH ASSY
a. Remove the unlock warning switch.
b. Measure the resistance of the switch.
Standard:
UNLOCK WARNING SWITCH - RESISTANCE TABLE
ItemDisplay (Range)Normal ConditionDiagnostic Note
KEY SWUnlock warning switch
signal/ ON or OFFON: Key is in ignition
key cylinder OFF: No
key is in ignition key
cylinder-
Tester ConnectionSwitch PositionSpecified Condition
3 - 4Ignition switch pushedBelow 1 ohms
3 - 4Ignition switch not pushed10 kohms or higher
2 - 4Key inserted in ignition key
cylinderBelow 1 ohms
2 - 4No key in ignition key cylinder10 kohms or higher

Fig. 31: Inspecting Unlock Warning Switch Assy
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPLACE UNLOCK WARNING SWITCH ASSY
OK: Go to next step
3.CHECK WIRE HARNESS (UNLOCK WARNING SWITCH ASSY - BODY GROUND)
a. Disconnect the U7 switch connector.
b. Measure the resistance of the wire harness side connector.
Standard:
UNLOCK WARNING SWITCH ASSY - BODY GROUND - RESISTANCE TABLE

Fig. 32: Checking Wire Harness (Unlock Warning Switch Assy - Body Ground)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: Go to next step
4.CHECK WIRE HARNESS (STEERING LOCK ECU - UNLOCK WARNING SWITCH ASSY)
a. Disconnect the S46 ECU connector.
b. Disconnect the U7 switch connector.
c. Measure the resistance of the wire harness side connectors.
Tester connectionSpecified condition
U7-4 - Body groundBelow 1 ohms

Standard:
STEERING LOCK ECU - UNLOCK WARNING SWITCH - RESISTANCE TABLE
Tester connectionSpecified condition
S46-12 (KSW) - U7-2Below 1 ohms
S46-11 (PUSH) - U7-3Below 1 ohms

Fig. 33: Checking Wire Harness (Steering Lock ECU -Unlock Warning Switch Assy)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: REPLACE STEERING LOCK ECU
CIRCUIT DESCRIPTION
This DTC is output when: 1) during the key code registration, a key malfunction occurs; or 2) the key code was
unable to be registered properly. Follow the inspection procedure below.
TRANSPONDER CHIP MALFUNCTION DTC REFERENCE TABLE
INSPECTION PROCEDURE
1.RE-REGISTER KEY
a. Delete the DTC (See DTC CHECK/CLEAR
).
b. Re-register the key (See REGISTRATION
), and check that the engine starts with the key.
OK: Engine starts.
NG: REPLACE KEY
OK: NORMAL (INSPECTION FINISHED)
CIRCUIT DESCRIPTION
This DTC is output when a key with an incomplete key code is inserted into the ignition key cylinder.
UNMATCHED ENCRYPTION CODE DTC REFERENCE TABLE
INSPECTION PROCEDURE
REPLACE KEY
DTC No.DTC Detection ConditionTrouble Area
B2793Transponder chip malfunctionSmart key
DTC No.DTC Detection ConditionTrouble Area
B2794Key with incomplete key code is
insertedSmart key