Dynamic Radar Cruise Control System

CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: C1A05, C1A4B: Stop Light Switch Circuit
C1A4B - Stop Light Relay Circuit

DESCRIPTION

When the brake pedal is depressed, the stop light switch sends a signal to the driving support ECU. Upon receiving the signal, the driving support ECU cancels speed control by 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 the fail-safe function. Dynamic radar cruise control speed control operation is canceled when battery voltage is applied to terminal STP-.

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

The brake booster with master cylinder (skid control ECU) receives a signal from the driving support ECU and operates the brake actuator. The brake booster with master cylinder (skid control ECU) operates the brake actuator and at the same time illuminates the stop lights by operating the stop light control relay.

The stop light switch assembly sends a brake pedal operation signal to the driving support ECU.

After receiving the signal, the ECM performs fail-safe control by canceling cruise control system control of vehicle speed.





WIRING DIAGRAM





INSPECTION PROCEDURE

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

PROCEDURE

1. CHECK STOP LIGHT OPERATION

(a) Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

OK:





NG -- GO TO LIGHTING SYSTEM
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Radar Cruise / Data List.

(e) 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 -- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - POWER SOURCE)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU)

(a) Disconnect the stop light switch assembly connector.

(b) Disconnect the brake booster with master cylinder (skid control ECU) connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the stop light switch assembly connector.

(e) Reconnect the brake booster with master cylinder (skid control ECU) connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU)
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - SKID CONTROL ECU)

(a) Disconnect the stop light control relay assembly connector.

(b) Disconnect the brake booster with master cylinder (skid control ECU) connectors.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(d) Reconnect the stop light control relay connector.

(e) Reconnect the brake booster with master cylinder (skid control ECU) connectors.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT CONTROL RELAY - SKID CONTROL ECU)
OK -- Continue to next step.

5. INSPECT STOP LIGHT CONTROL RELAY

(a) Inspect the stop light control relay Testing and Inspection.

NG -- REPLACE STOP LIGHT CONTROL RELAY Removal
OK -- Continue to next step.

6. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER (SKID CONTROL ECU)

(a) Replace the brake booster with master cylinder (skid control ECU) Removal.

NEXT -- Continue to next step.

7. CHECK FOR DTCs (DTC C1A05 OR C1A4B)

(a) Connect the Techstream to the DLC3.

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

(c) Clear the DTCs Dynamic Radar Cruise Control System.

(d) Perform the following to make sure that the DTC detection conditions are met.

HINT
If the detection conditions are not met, the malfunction cannot be detected.

(1) Drive the vehicle at a speed of between approximately 50 km/h (30 mph) and 170 km/h (105 mph).

(2) Turn the cruise control system on using the cruise control switch (ON-OFF button).

(3) Push the cruise control switch to -/SET to begin control of vehicle speed using the cruise control system.

(e) Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.

(f) Check for DTCs.

Result:





B -- REPLACE POWER MANAGEMENT CONTROL ECU

A -- END

8. REPLACE POWER MANAGEMENT CONTROL ECU

(a) Replace the power management control ECU Removal.

NEXT -- Continue to next step.

9. CHECK FOR DTCs (DTC C1A05 OR C1A4B)

(a) Connect the Techstream to the DLC3.

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

(c) Clear the DTCs Dynamic Radar Cruise Control System.

(d) Perform the following to make sure that the DTC detection conditions are met.

HINT
If the detection conditions are not met, the malfunction cannot be detected.

(1) Drive the vehicle at a speed of between approximately 50 km/h (30 mph) and 170 km/h (105 mph).

(2) Turn the cruise control system on using the cruise control switch (ON-OFF button).

(3) Push the cruise control switch to -/SET to begin control of vehicle speed using the cruise control system.

(e) Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.

(f) Check for DTCs.

Result:





B -- REPLACE DRIVING SUPPORT ECU Removal

A -- END

10. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - POWER SOURCE)

(a) Disconnect the stop light switch assembly connector.





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

Standard Voltage:





Standard Resistance:





Text in Illustration





(c) Reconnect the stop light switch assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH - IG2 RELAY)
OK -- Continue to next step.

11. INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Remove the stop light switch assembly Removal.





Text in Illustration





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

Standard Voltage:





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

12. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - DRIVING SUPPORT ECU)

(a) Disconnect the driving support ECU connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





(c) Reconnect the stop light switch assembly connector.

(d) Reconnect the driving support ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - DRIVING SUPPORT ECU)
OK -- Continue to next step.

13. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY GROUND)

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

Standard Resistance (Check for Short):





(b) Reconnect the stop light switch assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY GROUND)

OK -- REPLACE DRIVING SUPPORT ECU Removal