Lane-Keeping Assist System

CRUISE CONTROL: LANE-KEEPING ASSIST SYSTEM: C1A05: Stop Light Switch Circuit
C1A05 - Stop Light Switch Circuit

DESCRIPTION

When the brake pedal is depressed, the stop light switch assembly sends signal to the driving support ECU.

Receiving the signal, the driving support ECU cancels the dynamic radar cruise control system. Even if there is a malfunction in the stop light signal circuit while the cruise control is operating, normal driving is maintained due to fail-safe function.

When the brake pedal is depressed, positive voltage is applied to terminal STP- of the driving support ECU through the STOP fuse and the stop light switch assembly, and the driving support ECU cancels the cruise control.

When the brake pedal is released, positive voltage is applied to terminal ST1- of the driving support ECU through the IGN fuse and the stop light switch assembly, and the driving support ECU operates the dynamic radar cruise control.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

* STP signal conditions can be checked using the Techstream.

a. Connect the power switch on (IG).

b. Turn the power switch on (IG).

c. Enter the following menus: Powertrain / Radar Cruise / Data List / Stop Light SW 1 (M-CPU).

d. Check the STP signal when the brake pedal is depressed and released.





PROCEDURE

1. CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)

(a) Disconnect the stop light switch assembly connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reconnect the stop light switch assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT FOR STOP LIGHT SWITCH ASSEMBLY)
OK -- Continue to next step.

2. INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Disconnect the stop light switch assembly connector.





(b) Remove the stop light switch assembly.

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

Standard Resistance:





Text in Illustration





(d) Reinstall the stop light switch assembly.

(e) Reconnect the stop light switch assembly connector.

NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY Removal
OK -- Continue to next step.

3. CHECK DRIVING SUPPORT ECU (STP- AND ST1 - VOLTAGE)

(a) Disconnect the driving support ECU connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reconnect the driving support ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE DRIVING SUPPORT ECU Removal