DYNAMIC RADAR CRUISE CONTROL SYSTEM(for 1AR-FE), Diagnostic DTC:P0571

DESCRIPTION

Detection condition 1:

• 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. The cancellation condition occurs when voltage is applied to terminal STP. When the brake is 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 system off.

Detection condition 2:

• When the brakes are applied by the dynamic radar cruise control system, the skid control ECU (brake actuator assembly) operates the stop light switch assembly (stop light relay) to illuminate the stop lights.

  If the ECM receives a stop light switch control relay malfunction signal from the skid control ECU (brake actuator assembly), DTC P0571 is stored.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK FOR DTCs (PRE-COLLISION SYSTEM)

   
   

   1. Check for DTCs of the pre-collision system.

      Click here

      
      Body Electrical > Pre-Collision 2 > Trouble Codes

      Tech Tips

      When DTC P0571 is stored by the dynamic radar cruise control system, DTC C1A4B may be stored by the pre-collision system. Therefore, if DTC P0571 is stored, inspect the pre-collision system first.

      Result
      Result Proceed to DTC C1A4B is output A DTC C1A4B is not output B

   
   

   A

   GO TO PRE-COLLISION SYSTEM Click here

   B

2. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY AND BODY GROUND)

   
   
   1. 

      *a	Front view of wire harness connector (to Stop Light Switch Assembly)

      Disconnect the A87 stop light switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A87-2 (GND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition A87-7 (B) - Body ground Always 11 to 14 V A87-6 (B) - Body ground Engine switch on (IG) 11 to 14 V A87-6 (B) - Body ground Engine switch off Below 1 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. INSPECT STOP LIGHT SWITCH ASSEMBLY

   
   

   1. Inspect the stop light switch assembly.

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

   OK

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

   
   

   1. Disconnect the A43 ECM connector.

   2. Disconnect the A87 stop light switch assembly connector.

   3. Disconnect the A86 skid control ECU (brake actuator assembly) connector.

   4. Disconnect the F10 certification ECU (smart key ECU assembly) connector.

   5. Disconnect the F48 transmission floor shift assembly (shift lock control unit) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition A43-24 (ST1-) - A87-5 (L) Always Below 1 Ω A43-11 (STP) - A87-3 (L) Always Below 1 Ω A43-24 (ST1-) or A87-5 (L) - Body ground Always 10 kΩ or higher A43-11 (STP) or A87-3 (L) - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE ECM Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR