Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001GYXC
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM (for 2ZR-FAE): P0571; Stop Light Switch Circuit Malfunction; 2020 - 2022 MY Corolla [01/2019 - 09/2022]

DTC

P0571

Stop Light Switch Circuit Malfunction

DESCRIPTION

  • 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 control relay) to illuminate the stop lights.
  • If the ECM receives a signal from the skid control ECU (brake actuator assembly) indicating a malfunction of the stop light control relay, DTC P0571 is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

P0571

Stop Light Switch Circuit Malfunction

When the dynamic radar cruise control system is operating, the ECM detects a signal indicating a stop light control relay malfunction from the skid control ECU (brake actuator assembly) for approximately 0.5 second or more.

Condition 1:

  • Electronically controlled brake system

Condition 2:

  • Harness or connector
  • Stop light switch assembly
  • ECM

Cruise Control

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • Before replacing the ECM, refer to Registration.

    w/o Smart Key System: Click here 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2019]; THEFT DETERRENT / KEYLESS ENTRY: IMMOBILISER SYSTEM (w/o Smart Key System): REGISTRATION 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: IMMOBILISER SYSTEM (w/o Smart Key System): REGISTRATION 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: IMMOBILISER SYSTEM (w/o Smart Key System): REGISTRATION

    w/ Smart Key System: Click here 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2020 MY Corolla Corolla Hatchback GR Corolla [09/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION 2021 - 2022 MY Corolla Corolla Hatchback GR Corolla [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

PROCEDURE

1.

CHECK FOR DTCs

(a) Check if electronically controlled brake system DTCs are output.

Chassis > Brake > Trouble Codes

Result

Proceed to

Electronically controlled brake system DTCs are not output

A

Electronically controlled brake system DTCs are output

B
B

GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

w/ Electric Parking Brake System: Click here 2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 09/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model with Electric Parking Brake System): HOW TO PROCEED WITH TROUBLESHOOTING

w/o Electric Parking Brake System: Click here 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2022]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for Gasoline Model without Electric Parking Brake System): HOW TO PROCEED WITH TROUBLESHOOTING

A

2.

CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - POWER SOURCE AND BODY GROUND)

(a) Disconnect the A53 stop light switch assembly connector.

*a

Front view of wire harness connector

(to Stop Light Switch Assembly)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A53-2 (GND) - Body ground

Always

Below 1 Ω

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A53-7 (B) - Body ground

Always

11 to 14 V

A53-6 (B) - Body ground

Ignition switch ON

11 to 14 V

A53-6 (B) - Body ground

Ignition switch off

Below 1 V

(d) Connect the A53 stop light switch assembly connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Inspect the stop light switch assembly.

Click here 2020 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 -        ]; LIGHTING (EXT): STOP LIGHT SWITCH: ON-VEHICLE INSPECTION

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY

OK

4.

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

(a) Disconnect the A46 ECM connector.

(b) Disconnect the A53 stop light switch assembly connector.

(c) Disconnect the A51 skid control ECU (brake actuator assembly) connector.*4

(d) Disconnect the A100 skid control ECU (brake actuator assembly) connector.*5

(e) Disconnect the O61 certification ECU (smart key ECU assembly) connector.*1

(f) Disconnect the I17 shift lock control ECU (shift lock control unit assembly) connector.*2

(g) Disconnect the I18 shift lock control ECU (shift lock control unit assembly) connector.*3

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A53-5 (L) - A46-10 (ST1-)

Always

Below 1 Ω

A53-3 (L) - A46-9 (STP)

Always

Below 1 Ω

A53-5 (L) or A46-10 (ST1-) - Body ground

Always

10 kΩ or higher

A53-3 (L) or A46-9 (STP) - Body ground

Always

10 kΩ or higher

(i) Connect the I18 shift lock control ECU (shift lock control unit assembly) connector.*3

(j) Connect the I17 shift lock control ECU (shift lock control unit assembly) connector.*2

(k) Connect the O61 certification ECU (smart key ECU assembly) connector.*1

(l) Connect the A100 skid control ECU (brake actuator assembly) connector.*5

(m) Connect the A51 skid control ECU (brake actuator assembly) connector.*4

(n) Connect the A53 stop light switch assembly connector.

(o) Connect the A46 ECM connector.

  • *1: w/ Smart Key System
  • *2: for CVT without Smart Key System
  • *3: for CVT with Smart Key System
  • *4: w/ Electrical Parking Brake System
  • *5: w/o Electrical Parking Brake System
OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR