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Home >> Lexus >> 2012 >> IS 250C V6-2.5L (4GR-FSE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0571 >> Dynamic Radar Cruise Control System >> Part 2

Part 2





CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: P0571, P0571: Stop Light Switch Circuit Malfunction
P0571 - Brake Switch "A" Circuit - Continued

11. REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU)

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

NEXT -- Continue to next step.

12. CHECK WHETHER DTC OUTPUT RECURS (DTC P0571)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

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

(e) 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 50 km/h (30 mph) or more.

(2) Turn the cruise control main switch on.

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

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

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

Result:





B -- REPLACE ECM (for 2GR-FSE) Removal

C -- REPLACE ECM (for 4GR-FSE) Removal

A -- END

13. 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
OK -- Continue to next step.

14. 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.

15. 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.

16. 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 (Check for Open):





Standard Resistance (Check for Short):





Text in Illustration





(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 -- Continue to next step.

17. CHECK HARNESS AND CONNECTOR

(a) Disconnect the stop light switch assembly connector.





(b) Disconnect the ECM connector.

(c) Disconnect the stop light control relay connector.

(d) Disconnect the skid control ECU connector.

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

Standard Resistance (Check for Short):





Result:





Text in Illustration





(f) Reconnect the stop light switch assembly connector.

(g) Reconnect ECM connector.

(h) Reconnect the stop light control relay connector.

(i) Reconnect the skid control ECU connector.

B -- REPLACE ECM (for 2GR-FSE) Removal

C -- REPLACE ECM (for 4GR-FSE) Removal

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR

18. CHECK HARNESS AND CONNECTOR

(a) Disconnect the stop light switch assembly connector.





(b) Disconnect the stop light control relay connector.

(c) Remove the BRK-LP relay from the No. 2 engine room relay block.

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

Standard Resistance (Check for Short):





Text in Illustration





(e) Reconnect the stop light switch assembly connector.

(f) Reconnect the stop light control relay connector.

(g) Reinstall the BRK-LP relay.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

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

19. INSPECT MAIN BODY ECU LH (LH-IG1 RELAY)

(a) Disconnect the main body ECU LH connectors.





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

Standard Resistance:





Text in Illustration





(c) Reconnect the main body ECU LH connectors.

NG -- REPLACE MAIN BODY ECU LH (LH-IG1 RELAY)
OK -- Continue to next step.

20. CHECK HARNESS AND CONNECTOR (BRK-LP RELAY - MAIN BODY ECU LH)

(a) Remove the BRK-LP relay from the No. 2 engine room relay block.





(b) Disconnect the main body ECU LH connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





Text in Illustration





(d) Reinstall the BRK-LP relay.

(e) Reconnect the main body ECU LH connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (BRK-LP RELAY - MAIN BODY ECU LH)
OK -- Continue to next step.

21. CHECK MAIN BODY ECU LH (TERMINAL VOLTAGE)

(a) Disconnect the main body ECU LH connector.





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

Standard Voltage:





Text in Illustration





(c) Reconnect the main body ECU LH connector.

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

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

(a) Disconnect the main body ECU LH connector.





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

Standard Resistance (Check for Open):





Text in Illustration





(c) Reconnect the main body ECU LH connector.

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

23. CHECK HARNESS AND CONNECTOR (LH-IG1 RELAY - POWER SOURCE CONTROL ECU)

(a) Disconnect the main body ECU LH connector.





(b) Disconnect the power source 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):





Text in Illustration





(d) Reconnect the main body ECU LH connector.

(e) Reconnect the power source control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (LH-IG1 RELAY - POWER SOURCE CONTROL ECU)

OK -- GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START
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