DYNAMIC RADAR CRUISE CONTROL SYSTEM(for 2GR-FE, 2AR-FE), Diagnostic DTC:P0571

DESCRIPTION

• 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.

• The ECM receives the brake demand signal from the driving support ECU assembly and transmits it to the skid control ECU (brake actuator assembly). The skid control ECU (brake actuator assembly) receives a signal from the ECM and operates the skid control ECU (brake actuator assembly). The skid control ECU (brake actuator assembly) operates the brake actuator assembly and at the same time illuminates the stop light by operating the No. 1 integration relay.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK STOP LIGHT OPERATION

   
   

   1. Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

      OK
      Condition Illumination Condition Brake pedal depressed ON Brake pedal released OFF

   
   

   NG

   GO TO LIGHTING SYSTEM (EXT) Click here

   OK

2. READ VALUE USING GTS (BRAKE CANCEL SWITCH)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Enter the following menus: Powertrain / Radar Cruise1 / Data List.

   5. Check the Data List for proper functioning of the stop light switch.

      Radar Cruise1

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Brake Cancel Switch	Stop light switch status / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

      OK
      Display changes according to brake pedal operation described in above table.

   6. Turn the engine switch off.

   
   

   NG

   CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH POWER SOURCE CIRCUIT) Click here

   OK

3. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU)

   
   

   1. Disconnect the A28 stop light switch assembly connector.

   2. Disconnect the A69 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition A28-2 (L) - A69-35 (STP) Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition A28-2 (L) or A69-35 (STP) - Body ground Always 10 kΩ or higher

   4. Reconnect the A69 skid control ECU (brake actuator assembly) connector.

   5. Reconnect the A28 stop light switch assembly connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

4. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - SKID CONTROL ECU)

   
   

   1. Disconnect the 1F and 1G No. 1 integration relay connectors.

   2. Disconnect the A69 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition 1F-11 (STOP) - A69-5 (STP2) Always Below 1 Ω 1F-16 (STPS) - A69-35 (STP) Always Below 1 Ω 1G-3 (ACC) - A69-26 (STPO) Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition 1F-11 (STOP) or A69-5 (STP2) - Body ground Always 10 kΩ or higher 1F-16 (STPS) or A69-35 (STP) - Body ground Always 10 kΩ or higher 1G-3 (ACC) or A69-26 (STPO) - Body ground Always 10 kΩ or higher

   4. Reconnect the A69 skid control ECU (brake actuator assembly) connector.

   5. Reconnect the 1F and 1G No. 1 integration relay connectors.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

5. INSPECT NO. 1 INTEGRATION RELAY

   Click here

   
   

   NG

   REPLACE NO. 1 INTEGRATION RELAY Click here

   OK

6. REPLACE BRAKE ACTUATOR ASSEMBLY

   Click here

   
   

   NEXT

7. CHECK FOR DTCs (DTC P0571)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Clear the DTCs Click here.

   4. Make sure that the DTC detection conditions are met.

      Tech Tips

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

   5. Enter the following menus: Powertrain / Radar Cruise1 / Trouble Codes.

   6. Check for DTCs.

      Result
      Result Proceed to DTC is not output A DTC P0571 is output (for 2GR-FE) B DTC P0571 is output (for 2AR-FE) C

   7. Turn the engine switch off.

   
   

   A

   END

   B

   REPLACE ECM Click here

   C

   REPLACE ECM Click here

8. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH POWER SOURCE CIRCUIT)

   
   

   1. Disconnect the A28 stop light switch assembly connector.

   2. 

      Text in Illustration

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition A28-1 (B) - A28-3 (GND) Always 11 to 14 V A28-5 (B) - A28-3 (GND) Engine switch on (IG) 11 to 14 V

      Standard Resistance
      Tester Connection Condition Specified Condition A28-3 (GND) - Body ground Always Below 1 Ω

   3. Reconnect the A28 stop light switch assembly connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

9. INSPECT STOP LIGHT SWITCH ASSEMBLY

   
   
   1. 

      Text in Illustration

      *a	Component with harness connected (Stop Light Switch Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition A28-2 (L) - A28-3 (GND) Brake pedal not depressed Below 1 V Brake pedal depressed 11 to 14 V A28-4 (L) - A28-3 (GND) Engine switch on (IG), brake pedal not depressed 11 to 14 V Engine switch on (IG), brake pedal depressed Below 1 V

   
   

   NG

   REPLACE STOP LAMP SWITCH ASSEMBLY Click here

   OK

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

    
    

    1. Disconnect the A22 or A64 ECM connector.

    2. Disconnect the A28 stop light switch assembly connector.

    3. Disconnect the 1F and 1G No. 1 integration relay connectors.

    4. Disconnect the A69 skid control ECU (brake actuator assembly) connector.

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

       Standard Resistance (Check for Open)
       for 2GR-FE: Tester Connection Condition Specified Condition A22-51 (STP) - A28-2 (L) Always Below 1 Ω A22-36 (ST1-) - A28-4 (L) Always Below 1 Ω
       for 2AR-FE: Tester Connection Condition Specified Condition A64-11 (STP) - A28-2 (L) Always Below 1 Ω A64-24 (ST1-) - A28-4 (L) Always Below 1 Ω

       Standard Resistance (Check for Short)
       for 2GR-FE: Tester Connection Condition Specified Condition A22-51 (STP) or A28-2 (L) - Body ground Always 10 kΩ or higher A22-36 (ST1-) or A28-4 (L) - Body ground Always 10 kΩ or higher
       for 2AR-FE: Tester Connection Condition Specified Condition A64-11 (STP) or A28-2 (L) - Body ground Always 10 kΩ or higher A64-24 (ST1-) or A28-4 (L) - Body ground Always 10 kΩ or higher

       Result
       Result Proceed to OK (for 2GR-FE) A OK (for 2AR-FE) B NG C

    6. Reconnect the A69 skid control ECU (brake actuator assembly) connector.

    7. Reconnect the 1F and 1G No. 1 integration relay connectors.

    8. Reconnect the A28 stop light switch assembly connector.

    9. Reconnect the A22 or A64 ECM connector.

    
    

    A

    REPLACE ECM Click here

    B

    REPLACE ECM Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR