Stop Light Switch Circuit Malfunction

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

DTC P0571 - Stop Light Switch Circuit Malfunction

DESCRIPTION

The hybrid vehicle control ECU receives the brake demand signal from the distance control ECU (cruise control ECU) and transmits it to the skid control ECU.
The skid control ECU receives a signal from the hybrid vehicle control ECU and operates the brake actuator.
The skid control ECU operates the brake actuator and illuminates the stop light by operating the BRK relay at the same time.






WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

1. CHECK BRK RELAY





(a) Remove the BRK relay from the engine room R/B No. 1.
(b) Check operation of the BRK relay.
Standard resistance:






NG -- REPLACE BRK RELAY
OK -- Continue to next step.
2. CHECK WIRE HARNESS AND CONNECTOR (BRK RELAY - BATTERY)





(a) Disconnect the connector from the engine room R/B.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED FAILURE RELAY (BRK RELAY)
OK -- Continue to next step.
3. CHECK WIRE HARNESS AND CONNECTOR (BRK RELAY - SKID CONTROL ECU)





(a) Disconnect the connectors from the skid control ECU.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE SKID CONTROL ECU