Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE USING Intelligent tester OR TECHSTREAM (CRUISE CONTROL SWITCH)

Check the DATA LIST for proper functioning of the cruise control switch.

Intelligent tester

RADAR CRUISE

DIAGNOSTIC NOTE NORMAL CONDITION CHART

Tester Display	Measurement Item/Range	Normal Condition
MAIN SW	Cruise control switch signal (M-CPU)/ON or OFF	ON Cruise control switch is ON OFF Cruise control switch is OFF
SET/COAT SW	-/SET switch signal/ON or OFF	ON -/SET switch ON OFF -/SET switch OFF
RES/ACC SW	+/RES switch signal/ON or OFF	ON +/RES switch ON OFF +/RES switch OFF

Techstream

Radar Cruise

DIAGNOSTIC NOTE NORMAL CONDITION CHART

Tester Display	Measurement Item/Range	Normal Condition
Cruise Control Main Switch	Cruise control switch signal (Main CPU)/ON or OFF	ON Cruise control switch is ON OFF Cruise control switch is OFF
SET/COAT Switch	-/SET switch signal/ON or OFF	ON -/SET switch ON OFF -/SET switch OFF
RES/ACC Switch	+/RES switch signal/ON or OFF	ON +/RES switch ON OFF +/RES switch OFF

OK: When cruise control switch operation is performed, the results are same as above.

NG: Go to step 2

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See PROBLEM SYMPTOMS TABLE ).

INSPECT CRUISE CONTROL SWITCH

Remove the stop light switch (see REMOVAL ).
Measure the resistance according to the value (s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Switch Condition	Specified Condition
1 - 3	RES/ACC switch is held ON	235 to 245 Ω
1 - 3	SET/COAST switch is held ON	617 to 643 Ω
1 - 3	CANCEL switch is held ON	1509 to 1571 Ω
1 - 3	Cruise control switch OFF	1MΩ or higher
1 - 3	Cruise control switch ON	Below 2.5 Ω
1 - 2	MODE switch is held ON	Below 2.5 Ω

Fig 1: Identifying Cruise Control Switch & Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE CRUISE CONTROL SWITCH (See REMOVAL ).

OK: Go to next step

INSPECT SPIRAL CABLE SUB-ASSEMBLY

Fig 2: Identifying Cruise Control Switch Connector Z2 And Driving Support ECU Connector L24

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the z2 and L24 cable connectors.
Measure the resistance according to the value (s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Condition	Condition	Specified Condition
z2-3 - L24-1 (CCS)	Always	Below 1 Ω
z2-3 - L24-7 (R/N)	Always	Below 1 Ω
z2-1 - L24-2 (ECC)	Always	Below 1 Ω

NG: REPLACE SPIRAL CABLE SUB-ASSEMBLY (See REMOVAL ).

OK: Go to next step

INSPECT CRUISE CONTROL SWITCH WIRE

Disconnect the z2 cable connector
Disconnect the A switch connector.
Measure the resistance according to the value (s) in the table below

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
z2-3 - A-3	Always	Below 1 Ω
z2-4 - A-1	Always	Below 1 Ω
z2-1 - A-2	Always	Below 1 Ω
A-3 - Body ground	Always	10 kΩ or higher
A-1 - Body ground	Always	10 kΩ or higher
A-2 - Body ground	Always	10 kΩ or higher

Fig 3: Identifying Z2 Cable Connector And A Switch Connector

NG: REPLACE CRUISE CONTROL SWITCH WIRE

CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - DRIVING SUPPORT ECU AND BODY GROUND)

Disconnect the L24 cable connector.
Disconnect the A33 ECU connector.

Measure the resistance according to the value (s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
L24-1 (CCS) - A33-30 (CCHG)	Always	Below 1 Ω
L24-7 (R/N) - A33-27 (CCS)	Always	Below 1 Ω
L24-2 (ECC) - Body ground	Always	Below 1 Ω
L24-1 (CCS) - Body ground	Always	10 kΩ or higher
L24-7 (R/N) - Body ground	Always	10 kΩ or higher

Fig 4: Identifying L24 Cable Connector And Driver Support ECU A33 Connector

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE DRIVING SUPPORT ECU (See REMOVAL ).