Inspection Procedure

WARNING: This page is about a different car, the 2002 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE OF LEXUS HAND-HELD TESTER (KEY SW)

ECU DATA MONITOR

Make a judgement of good or bad and find out a malfunctioning part by the data monitor.

Standard:

TRANSPONDER KEY ECU (SWITCH CONDITION)

SPECIFIED CONDITION

Item	Condition	Specified condition
KEY SW	Ignition switch ON --> Without key	ON/OFF

OK: CHECK AND REPLACE TRANSPONDER KEY ECU ASSEMBLY
NG: GO TO NEXT STEP

INSPECT UN-LOCK WARNING SWITCH ASSEMBLY

Check the continuity between terminals 1 and 2 of the connector.
Standard:

CONTINUITY

Operation	Continuity
Pin not pushed in	No continuity
Pin pushed in	Continuity

Fig 1: Inspecting Un-Lock Warning Switch Assembly

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE UN-LOCK WARNING SWITCH ASSEMBLY
OK: GO TO NEXT STEP

CHECK WIRE HARNESS (TRANSPONDER KEY ECU - UN-LOCK SWITCH)

Disconnect the transponder key ECU and UN-LOCK warning switch connectors.
Check the continuity between each terminal of the transponder key ECU vehicles side connector and UN-LOCK warning switch vehicles side connector. See TERMINALS OF ECU .
Standard:

SPECIFIED CONDITION

Terminals (ECU - UN-LOCK Switch)	Specified condition
T13-3 <=> U1-2 (KSW <=> UN-LOCK switch)	Continuity

Fig 2: Checking Wire Harness Transponder Key ECU - Un-Lock Switch

NG: REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR
OK: CHECK AND REPLACE TRANSPONDER KEY ECU ASSEMBLY