Lexus TechDoc

DYNAMIC RADAR CRUISE CONTROL SYSTEM > Cruise Control Switch Circuit

for Preparation Click here

DESCRIPTION

The cruise control switch operates 8 functions: SET, -(COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP, CANCEL, and MODE. The SET, TAP-DOWN, and - (COAST) functions, and the RES (RESUME), TAP-UP, and + (ACCEL) functions are operated with the same switch. The cruise control switch is an automatic return type switch which turns on only while it is being operated it in the direction of each arrow and turns off after being released. The internal contact points of the cruise control switch are turned on with the switch operation. The driving support ECU then reads the voltage value that has been changed by the switch operation to control MODE, SET, -, RES, +, and CANCEL. The dynamic radar cruise control system has two cruise control modes: constant speed control mode and vehicle-to-vehicle distance control mode.

Vehicle-to-vehicle distance control mode is always selected when starting up the dynamic radar cruise control system.
The operation of constant speed control mode is the same as that for a conventional cruise control system.

WIRING DIAGRAM

INSPECTION PROCEDURE

1.INSPECT CRUISE CONTROL SWITCH

Remove the cruise control switch (Click here).

Text in Illustration
*1
Cruise control switch (ON-OFF button)
-
-
*a
Component without harness connected
(Cruise Control Switch)
*b
ON-OFF
*c
+/RES
*d
-/SET
*e
MODE
*f
CANCEL

Text in Illustration
*1	Cruise control switch (ON-OFF button)	-	-
*a	Component without harness connected (Cruise Control Switch)	*b	ON-OFF
*c	+/RES	*d	-/SET
*e	MODE	*f	CANCEL

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
1 - 2 1 - 3	Cruise control switch off	1 MΩ or higher
1 - 3	Cruise control switch on	Below 2.5 Ω
1 - 2	MODE	Below 2.5 Ω
1 - 3	+/RES	235 to 245 Ω
1 - 3	-/SET	617 to 643 Ω
1 - 3	CANCEL	1509 to 1571 Ω

Reinstall the cruise control switch (Click here).

REPLACE CRUISE CONTROL SWITCH (Click here)

OK

2.CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - CRUISE CONTROL SWITCH)

Disconnect the connector from the spiral with sensor cable sub-assembly.

Disconnect the connector from the cruise control switch.

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
Cruise control switch side connector terminal 1 - z5-4	Always	Below 1 Ω
Cruise control switch side connector terminal 2 - z5-1	Always	Below 1 Ω
Cruise control switch side connector terminal 3 - z5-3	Always	Below 1 Ω

Text in Illustration
*a	Front view of wire harness connector (to Spiral with Sensor Cable Sub-assembly)
*b	Front view of wire harness connector (to Cruise Control Switch)

Reconnect the connector to the spiral with sensor cable sub-assembly.

Reconnect the connector to the cruise control switch.

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - CRUISE CONTROL SWITCH)

OK

3.INSPECT SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY

NOTICE:

The spiral with sensor cable sub-assembly is an important part of the SRS airbag system. Incorrect removal or installation of the spiral with sensor cable sub-assembly may cause airbag deployment. Be sure to read the page shown in the link/brackets.

Remove the spiral with sensor cable sub-assembly (Click here).

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
z5-1 - H30-8 (R/N)	The spiral with sensor cable sub-assembly is centered	Below 1 Ω
	The spiral with sensor cable sub-assembly position is 2.5 rotations to the left
	The spiral with sensor cable sub-assembly position is 2.5 rotations to the right
z5-3 - H30-1 (CCS)	The spiral with sensor cable sub-assembly is centered	Below 1 Ω
	The spiral with sensor cable sub-assembly position is 2.5 rotations to the left
	The spiral with sensor cable sub-assembly position is 2.5 rotations to the right
z5-4 - H30-2 (ECC)	The spiral with sensor cable sub-assembly is centered	Below 1 Ω
	The spiral with sensor cable sub-assembly position is 2.5 rotations to the left
	The spiral with sensor cable sub-assembly position is 2.5 rotations to the right

Text in Illustration
*a	Component without harness connected (Spiral with Sensor Cable Sub-assembly)

HINT:

The spiral with sensor cable sub-assembly makes a maximum of approximately 5 rotations.

Install the spiral with sensor cable sub-assembly (Click here).

REPLACE SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY (Click here)

OK

4.CHECK HARNESS AND CONNECTOR (SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY - DRIVING SUPPORT ECU)

Disconnect the driving support ECU connector.

Disconnect the spiral with sensor cable sub-assembly connector.

Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Tester Connection
Condition
Specified Condition
H5-23 (CCS) - H30-1 (CCS)
Always
Below 1 Ω
H5-10 (CCHG) - H30-8 (R/N)
Always
Below 1 Ω
Standard Resistance (Check for Short):
Tester Connection
Condition
Specified Condition
H5-23 (CCS) or H30-1 (CCS) - Body ground
Always
10 kΩ or higher
H5-10 (CCHG) or H30-8 (R/N) - Body ground
Always
10 kΩ or higher

Reconnect the driving support ECU connector.

Reconnect the spiral with sensor cable sub-assembly connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY - DRIVING SUPPORT ECU)

OK

5.CHECK HARNESS AND CONNECTOR (SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY - BODY GROUND)

Disconnect the spiral with sensor cable sub-assembly connector.

Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Tester Connection
Condition
Specified Condition
H30-2 (ECC) - Body ground
Always
Below 1 Ω
Text in Illustration
*a
Front view of wire harness connector
(to Spiral with Sensor Cable Sub-assembly)

Reconnect the spiral with sensor cable sub-assembly connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY - BODY GROUND)

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)