Dynamic Radar Cruise Control System

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

DTC P0571 - Stop Light Switch Circuit Malfunction

DESCRIPTION

The ECM receives the brake demand signal from the stop light switch and transmits it to the master cylinder solenoid (skid control ECU). The master cylinder solenoid (skid control ECU) receives the signal from the ECM and operates the brake actuator.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (STOP, IGN, ECU-IG No. 2)
(a) Remove the STOP and IGN fuses from the engine room relay block.
(b) Remove the ECU-IG No. 2 fuse from the cowl side junction block LH.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPLACE FUSE
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)
(a) Using the Techstream, read the Data List.

Radar Cruise





OK:
Normal conditions listed above are displayed.
NG -- INSPECT STOP LIGHT SWITCH
OK -- Continue to next step.
3. INSPECT BRAKE LIGHT RELAY (BRK LP)





(a) Remove the brake light relay from the engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPLACE BRAKE LIGHT RELAY
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - BATTERY AND BODY GROUND)





(a) Disconnect the A39 stop light control relay connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:





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






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





(a) Disconnect the A39 stop light control relay connector.
(b) Disconnect the A30 stop light switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - BRAKE LIGHT RELAY)





(a) Disconnect the A39 stop light control relay connector.
(b) Remove the brake light relay from the engine room relay block.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. CHECK STOP LIGHT CONTROL RELAY





(a) Remove the stop light control relay with its connector still connected Testing and Inspection.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






NG -- REPLACE STOP LIGHT CONTROL RELAY
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (BRAKE LIGHT RELAY - BATTERY)





(a) Remove the brake light relay from the engine room relay block.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (BRK LP, STOP LIGHT CONTROL RELAY - MASTER CYLINDER SOLENOID)





(a) Disconnect the A24 master cylinder solenoid (skid control ECU) connector.
(b) Remove the brake light relay from the engine room relay block.
(c) Disconnect the A39 stop light control relay connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MASTER CYLINDER SOLENOID (SKID CONTROL ECU)
10. INSPECT STOP LIGHT SWITCH





(a) Disconnect the A30 stop light switch connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPLACE STOP LIGHT SWITCH
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - BATTERY)





(a) Disconnect the A30 stop light switch connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






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





(a) Disconnect the A38 ECM connector.
(b) Disconnect the A30 stop light switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM