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 assembly sends a signal to the ECM. When the ECM receives this signal, it cancels the dynamic radar cruise control. The fail-safe function operates to enable normal driving even if there is a malfunction in the stop light signal circuit. Cruise control cancellation occurs when voltage is applied to terminal STP. When the brakes are applied, voltage is normally applied to terminal STP of the ECM through the STOP fuse and the stop light switch assembly, and the ECM turns the dynamic radar cruise control off.

- The ECM receives the brake demand signal from the distance control ECU and transmits it to the skid control ECU. The skid control ECU receives a signal from the ECM and operates the brake actuator. The skid control ECU operates the brake actuator and at the same time illuminates the stop lights by operating the BRK relay.

WIRING DIAGRAM

INSPECTION PROCEDURE

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

HINT
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. CHECK ECM (TERMINAL VOLTAGE)

(a) Disconnect the ECM connector.

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

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

Standard Voltage:

Text in Illustration

(d) Reconnect the ECM connector.

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

2. CHECK BRK RELAY

(a) Remove the BRK relay from the engine room relay block.

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

Standard Resistance:

Text in Illustration

(c) Reinstall the BRK relay.

NG -- REPLACE BRK RELAY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BRK RELAY)

(a) Disconnect the stop light switch assembly connector.

(b) Remove the BRK relay from the engine room relay block.

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

Standard Resistance:

(d) Reconnect the stop light switch assembly connector.

(e) Reinstall the BRK relay.

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

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

(a) Disconnect the stop light switch assembly connector.

(b) Disconnect the skid control ECU connector.

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

Standard Resistance:

(d) Reconnect the stop light switch assembly connector.

(e) Reconnect the skid control ECU connector.

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

5. CHECK HARNESS AND CONNECTOR (BRK RELAY - ECM)

(a) Remove the BRK relay from the engine room relay block.

(b) Disconnect the ECM connector.

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

Standard Resistance:

(d) Reconnect the ECM connector.

(e) Reinstall the BRK relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (BRK RELAY - ECM)
OK -- Continue to next step.

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

(a) Remove the BRK relay from the engine room relay block.

(b) Disconnect the skid control ECU connector.

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

Standard Resistance:

(d) Reinstall the BRK relay.

(e) Reconnect the skid control ECU connector.

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

7. CHECK BRK RELAY (TERMINAL VOLTAGE)

(a) Remove the BRK relay from the engine room relay block.

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

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

Standard Voltage:

Text in Illustration

(d) Reinstall the BRK relay.

NG -- INSPECT IG1 RELAY
OK -- Continue to next step.

8. REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU)

(a) Replace the brake actuator assembly (skid control ECU) Removal.

NEXT -- Continue to next step.

9. CHECK WHETHER DTC OUTPUT RECURS (DTC P0571)

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

(b) 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 for which cruise control operation is possible.

(2) Turn the cruise control main switch on.

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

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

OK:

DTC is not output.

B -- REPLACE ECM 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 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 - BRK RELAY)
OK -- Continue to next step.

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

(a) Disconnect the stop light switch assembly connector.

(b) Turn the engine 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.

12. 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) Reinstall the stop light switch assembly Installation.

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

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

(a) Disconnect the stop light switch assembly connector.

(b) Disconnect the ECM connectors.

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

Standard Resistance:

(d) Reconnect the stop light switch assembly connector.

(e) Reconnect the ECM connectors.

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

OK -- REPLACE ECM Removal

14. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BRK RELAY)

(a) Disconnect the stop light switch assembly connector.

(b) Remove the BRK relay from the engine room relay block.

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

Standard Resistance:

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

Standard Resistance:

(c) Reinstall the IG1 relay.

NG -- REPLACE IG1 RELAY
OK -- Continue to next step.

16. CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK - INSTRUMENT PANEL J/B)

(a) Remove the BRK relay from the engine room relay block.

(b) Remove the IG1 relay from the instrument panel J/B.

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

Standard Resistance:

(d) Reinstall the IG1 relay.

(e) Reinstall the BRK relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK - INSTRUMENT PANEL J/B)
OK -- Continue to next step.

17. CHECK HARNESS AND CONNECTOR (IG1 RELAY POWER SOURCE CIRCUIT)

(a) Remove the IG1 relay from the instrument panel J/B.

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

Standard Voltage:

Text in Illustration

(c) Reinstall the IG1 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 RELAY POWER SOURCE CIRCUIT)
OK -- Continue to next step.

18. CHECK HARNESS AND CONNECTOR (IG1 RELAY - BODY GROUND)

(a) Remove the IG1 relay from the instrument panel J/B.

Text in Illustration

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

Standard Resistance:

(c) Reinstall the IG1 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 RELAY - BODY GROUND)
OK -- Continue to next step.

19. CHECK HARNESS AND CONNECTOR (IG1 RELAY - MAIN BODY ECU)

(a) Disconnect the main body ECU connector.

(b) Remove the IG1 relay from the instrument panel J/B.

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

Standard Resistance:

(d) Reconnect the main body ECU connector.

(e) Reinstall the IG1 relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 RELAY - MAIN BODY ECU)

OK -- GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START How To Proceed With Troubleshooting