Ignition Switch And Key Unlock Warning Switch: Inspection

WARNING: This page is about a different car, the 2005 Lexus GS 430 and 2005 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT IGNITION SWITCH CONTINUITY

Fig 1: Identifying Different Positions Of Ignition Switch

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

IGNITION SWITCH CONTINUITY

Switch position	Tester connection	Specified condition
LOCK	-	No continuity
ACC	2 - 3	Continuity
ON	2 - 3 - 4	Continuity
ON	6 - 7	Continuity
START	1 - 2 - 4	Continuity
START	6 - 7 - 8	Continuity

If continuity is not as specified, replace the switch.

INSPECT IGNITION SWITCH CIRCUIT

Connect the switch connector and inspect the connector on wire harness side from the back side, as shown.

Fig 2: Identifying Ignition Switch Connector (Harness Side)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CIRCUIT CONNECTOR

Tester connection	Condition	Specified condition
2 - Ground	Constant	Battery positive voltage
3 - Ground	Ignition switch ACC or ON	Battery positive voltage
4 - Ground	Ignition switch ON	Battery positive voltage
6 - Ground	Ignition switch ON or START	Battery positive voltage
7 - Ground	Constant	Battery positive voltage
8 - Ground	Ignition switch START	Battery positive voltage

If circuit is not as specified, inspect the circuits connected to other parts.

INSPECT IGNITION KEY ILLUMINATION OPERATION
Connect the positive (+) lead from the battery to terminal 1 and the negative (-) lead to terminal 2, and check that the indicator light lights up.

If operation is not as specified, replace the switch.

Fig 3: Identifying Ignition Key Illumination Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT IGNITION KEY ILLUMINATION CIRCUIT , (See ILLUMINATION CIRCUIT ).

INSPECT KEY UNLOCK WARNING SWITCH CONTINUITY

Fig 4: Inspecting Key Unlock Warning Switch Continuity

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

SWITCH POSITION CONTINUITY

Switch position	Tester connection	Specified condition
OFF (Key removed)	-	No continuity
ON (Key set)	1 - 2	Continuity

If continuity is not as specified, replace the switch.

INSPECT KEY UNLOCK WARNING SWITCH CIRCUIT , (See KEY UNLOCK WARNING SWITCH CIRCUIT ).

Connect the switch connector and inspect the connector on wire harness side from the back side, as shown.

Fig 5: Identifying Key Unlock Warning Switch Connector (Harness Side)

KEY UNLOCK, WARNING

Tester connection	Condition	Specified condition
1 - Ground	Constant	Continuity

If circuit is not as specified, inspect the circuits connected to other parts.