Dynamic Radar Cruise Control System

CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: P0571: Stop Light Switch Circuit Malfunction
P0571 - Stop Light Switch Circuit Malfunction

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 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 is canceled when positive battery voltage is applied to terminal STP-.

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, 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 control system. The brake booster with master cylinder (skid control ECU) operates the brake control system 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 hybrid vehicle control ECU performs fail-safe control by canceling the cruise control function.





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.
- When the DTC is output, malfunction in the lighting system is suspected. Check if the lighting system is functioning normally How To Proceed With Troubleshooting.

PROCEDURE

1. 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:

The display changes as shown above according to brake pedal operation.

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

2. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY POWER SOURCE)

(a) Disconnect the stop light control relay connector.





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

Standard Voltage:





Text in Illustration





(c) Reconnect the stop light control relay connector.

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

3. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - BODY GROUND)

(a) Disconnect the stop light control relay connector.





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

Standard Resistance:





Text in Illustration





(c) Reconnect the stop light control relay connector.

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

4. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - STOP LIGHT SWITCH ASSEMBLY)

(a) Disconnect the stop light control relay connector.

(b) Disconnect the stop light switch assembly 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 stop light control relay connector.

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

5. 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.

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

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

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

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

7. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the stop light control relay connector.

(b) Disconnect the power management 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 connectors.

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

8. INSPECT STOP LIGHT CONTROL RELAY

(a) Inspect the stop light control relay Component Tests and General Diagnostics.

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

9. 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.

10. CHECK WHETHER DTC OUTPUT RECORDS (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 40 km/h (25 mph) or more.

(2) Turn the cruise control main switch on.

(3) Push the -SET switch to activate the cruise control.

(4) Depress the brake pedal.

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

(f) Read the DTCs.

Result:





B -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

A -- END

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

(a) Disconnect the stop light switch assembly connector.





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

Standard Voltage:





Text in Illustration





(c) Reconnect the stop light switch assembly connector.

NG -- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - STOP LIGHT CONTROL RELAY)
OK -- Continue to next step.

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

(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 (STOP LIGHT SWITCH ASSEMBLY - IG2 RELAY)
OK -- Continue to next step.

13. INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Remove the stop light switch assembly Removal.





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

Standard Resistance:





Text in Illustration





(c) Install the stop light switch assembly Installation.

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

14. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

(a) Disconnect the stop light switch assembly connector.

(b) Disconnect the hybrid vehicle 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 Open):





(d) Reconnect the stop light switch assembly connector.

(e) Reconnect the hybrid vehicle control ECU connector.

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

15. CHECK HARNESS AND CONNECTOR

(a) Disconnect the stop light switch assembly connector.

(b) Disconnect the hybrid vehicle control ECU connector.

(c) Disconnect the stop light control relay connector.

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

(e) Disconnect the power management control ECU connector.

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

Standard Resistance (Check for Short):





(g) Reconnect the stop light switch assembly connector.

(h) Reconnect the hybrid vehicle control ECU connector.

(i) Reconnect the power management control ECU connector.

(j) Reconnect the stop light control relay connector.

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

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE HYBRID VEHICLE CONTROL ECU Removal

16. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - STOP LIGHT CONTROL RELAY)

(a) Disconnect the stop light switch assembly connector.

(b) Disconnect the stop light control relay connector.

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

Standard Resistance (Check for Short):





(d) Reconnect the stop light switch assembly connector.

(e) Reconnect the stop light control relay connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - STOP LIGHT CONTROL RELAY)

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY)