LEXUS LS430 2003 Factory Repair Manual

Fig. 20: Identifying Waveform 5
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3.CHECK ECM
Fig. 21: Checking ECM

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a. Disconnect the E2 and E4 ECM connectors.
b. Measure the voltage and resistance of the wire harness side connectors.

Standard:
ECM CONNECTORS - VOLTAGE AND RESISTANCE TABLE
If the result is not as specified, there may be a malfunction on the wire harness side.
c. Inspect using an oscilloscope.
Waveform 1 (Reference):
WAVEFORM 1 REFERENCE TABLE
Symbols
(Terminal No.)
Wiring Color
Terminal
Description
Condition
Specified
Condition
IMI (E2-6) - E01
(E4-2)GR-G - W-BSteering lock ECU
input signalNo key in ignition
key cylinder ->
Key insertedPulse generation
(see waveform 1)
IMO (E2-7) - E01
(E4-2)GR-R - W-BSteering lock ECU
output signalNo key in ignition
key cylinder ->
Key insertedPulse generation
(see waveform 2)
E01 (E4-2) - Body
groundW-B - Body
groundGroundAlwaysBelow 1 ohms
TerminalIMI - GND
Tool Setting10 V/DIV., 500 ms/DIV.
ConditionNo key in ignition key cylinder -> Key inserted

Fig. 22: Identifying Waveform 1
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Waveform 2 (Reference):
WAVEFORM 2 REFERENCE TABLE
TerminalIMO - GND
Tool Setting10 V/DIV., 500 ms/DIV.
ConditionNo key in ignition key cylinder -> Key inserted

Fig. 23: Identifying Waveform 2
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1.DESCRIPTION
a. The ECM controls the vehicle's immobilizer system functions. Immobilizer system data and the
Diagnostic Trouble Codes (DTCs) can be read through the vehicle's Data Link Connector 3
(DLC3). In some cases, a malfunction may be occurring in the immobilizer system even though the
security indicator lamp is not illuminated. When the system seems to be malfunctioning, use the
hand-held tester to check for malfunctions and perform repairs.
2.CHECK DLC3
HINT:
The vehicle uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3
complies with SAE J1962 and matches the ISO 15765-4 format.

Fig. 24: Checking DLC3
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DLC3
If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and
connector.
HINT:
Connect the cable of the hand-held tester (with CAN VIM) to the DLC3, turn the ignition switch ON and
attempt to use the hand-held tester. If the screen displays the message UNABLE TO CONNECT TO
VEHICLE, there is a problem either with the vehicle or with the tester.
Symbols (Terminals
No.)
Terminal DescriptionConditionSpecified Condition
SIL (7) - SG (5)Bus "+" lineDuring transmissionPulse generation
CG (4) - Body groundChassis groundAlwaysBelow 1 ohms
SG (5) - Body groundSignal groundAlwaysBelow 1 ohms
BAT (16) - Body groundBattery positiveAlways11 to 14 V

If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of
the original vehicle.
If communication is still impossible when the tester is connected to another vehicle, the problem is
probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.
Fig. 25: Connecting Hand
-Held Tester To DLC3
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3.INSPECT BATTERY VOLTAGE
Standard: 11 to 14 V
If the voltage is below 11 V, replace the battery before proceeding.
1.CHECK DTC
a. Connect the hand-held tester to the Controller Area Network Vehicle Interface Module (CAN
VIM). Then connect the CAN VIM to the DLC3.
b. Turn the ignition switch ON.

c. Read the DTCs by following the directions on the tester screen.
HINT:
Refer to the hand-held tester operator's manual for further details.
Fig. 26: Connecting Hand
-Held Tester To DLC3
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2.CLEAR DTC
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON.
c. Erase the DTCs by following the directions on the tester screen.
HINT:
Refer to the hand-held tester operator's manual for further details.

1.DATA LIST
HINT:
Using the hand-held tester's DATA LIST allows switch, sensor, actuator and other item values to be read
without removing any parts. Reading the DATA LIST early in troubleshooting is one way to save time.
a. Connect the hand-held tester to the Controller Area Network Vehicle Interface Module (CAN
VIM). Then connect the CAN VIM to the DLC3.
b. Turn the ignition switch ON.
c. Read the DATA LIST.
Steering lock ECU:
DATA LIST - STEERING LOCK ECU
Item
Measurement Item/
Display (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-
IMMOBILIZERImmobilizer system
status/ SET or UNSETUNSET: Ignition switch
ON SET: Without key-
RESPONSETransponder chip data/
NG or OKNG: Data error OK: Data
OK-
FRAMETransponder chip data/
NG or OKNG: Data error OK: Data
OK-
SERIAL NUMBERTransponder chip data/
NG or OKNG: Data error OK: Data
OK-
ENCRYPT CODETransponder chip data/
NG or OKNG: Data error OK: Data
OK-
STATUSTransponder chip data/
NG or OKNG: Data error OK: Data
OK-
BCCTransponder chip signal/
NG or OKNG: Incorrect data
sending OK: Correct data
sending-
SUB KEYSub-key code signal/
NOMATCH or MATCHNOMATCH: Unmatched
sub-key code is sent
MATCH: Sub-key code
is sent-
MASTER KEYMaster key code signal/
NOMATCH or MATCHNOMATCH: Unmatched
Master key code is sent
MATCH: Master key
code is sent-
REGIST SUB CODENumber of registered Number of registered -

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

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2.ECM DTC CHART
Fig. 28: ECM DTC Chart

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DTC B2793TRANSPONDER CHIP MALFUNCTION
DTC B2794UNMATCHED ENCRYPTION CODE
DTC B2795UNMATCHED KEY CODE
DTC B2797COMMUNICATION MALFUNCTION NO.1
DTC B2799ENGINE IMMOBILIZER SYSTEM
MALFUNCTION