C1A05

CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: C1A05: Stop Light Switch Circuit

DTC C1A05 - Stop Light Switch Circuit

DESCRIPTION

When the brake pedal is depressed, the stop light switch sends signal to the driving support ECU.
Receiving the signal, the driving support ECU cancels the dynamic radar cruise control system. Even if these is a malfunction in the stop light signal circuit while the cruise control is in operation, normal driving is maintained due to fail-safe function. Dynamic radar cruise control is canceled when positive battery voltage is applied to terminal STP-.
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, 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 ECU-IG fuse and the stop light switch, and the driving support ECU operates the dynamic radar cruise control.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)
(a) Check the Data List for proper functioning of the stop light switch.

Radar Cruise





OK:
Display changes according to brake pedal operation described in above table.
NG -- INSPECT FUSE (STOP, ECU-IG)
OK -- REPLACE DRIVING SUPPORT ECU
2. INSPECT FUSE (STOP, ECU-IG)
(a) Remove the STOP fuse from the main body ECU.
(b) Remove the ECU-IG fuse from the engine room No. 2 junction block.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE FUSE
OK -- Continue to next step.

3. INSPECT STOP LIGHT SWITCH ASSEMBLY




(a) Remove the stop light switch Removal.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






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

4. CHECK HARNESS AND CONNECTOR (ECU - BATTERY)




(a) Disconnect the A33 ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE DRIVING SUPPORT ECU