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 ECM. Upon receiving the signal, the ECM cancels cruise control. Even if there is a malfunction in the stop light signal circuit while cruise control is in operation, normal driving is maintained due to a fail-safe function.

When the brake pedal is depressed, positive voltage is applied to terminal STP of the ECM through the STOP fuse and stop light switch, and the ECM cancels cruise control.

The skid control ECU receives a signal from the driving support ECU and operates the brake control system. The 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 ECM performs fail-safe control by canceling the cruise control function.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
- When the ECM is replaced with a new one, initialization must be performed Programming and Relearning.
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY)

(a) Use the Data List to check if the stop light switch is functioning properly Dynamic Radar Cruise Control System.

Radar Cruise





OK:

On screen, item changes between ON and OFF according to above chart.

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

2. CHECK FOR DTC (VEHICLE STABILITY CONTROL SYSTEM)

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

Vehicle stability control system DTCs are not output.

NG -- REPLACE VEHICLE STABILITY CONTROL SYSTEM Vehicle Stability Control System
OK -- Continue to next step.

3. CHECK FOR DTC

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

(b) Perform the following to make sure the DTC detection conditions are met.

HINT
If the detection conditions are not met, the system cannot detect the malfunction.

(1) Drive the vehicle at a speed of 50 km/h (30 mph) or more.

(2) Turn the cruise control switch on.

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

(c) Check for DTCs Dynamic Radar Cruise Control System.

OK:

DTC P0571 is not output.

NG -- REPLACE ECM Removal

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

4. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - BATTERY)

(a) Disconnect the A5 stop light switch connector.





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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Remove the stop light switch Removal.





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

Standard Resistance:





Text in Illustration





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

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

(a) Disconnect the A5 stop light switch connector.

(b) Disconnect the G44 and G45 ECM connectors.

(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 Removal