Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001JVPZ
Model Year Start: 2020 Model: Avalon HV Prod Date Range: [08/2019 - 08/2020]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): C1380; Stop Light Control Relay Malfunction; 2020 MY Avalon HV [08/2019 - 08/2020]

DTC

C1380

Stop Light Control Relay Malfunction

DESCRIPTION

When any of the following conditions are met, the skid control ECU (brake booster with master cylinder assembly) sets the drive output (STPO) ON which operates the stop light control relay (stop light switch assembly) and turns on the stop lights.

Illumination Conditions:

  • Pre-collision brake is operating.
  • The dynamic radar cruise control system is operating and is applying the brakes.
  • Secondary collision brake is operating.
  • Brake hold is operating.
  • The parking brake is engaged while the vehicle is being driven.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

MIL

Note

C1380

Stop Light Control Relay Malfunction

761

762
  • INF Code: 761
    • When terminal IG1 voltage is 9.5 V or more, stop light drive output (STPO) is on and STP2 is off for 2 seconds or more.
  • INF Code: 762
    • When terminal IG1 voltage is 9.5 V or more, stop light drive output (STPO) is off and the input signals for STP and STP2 differ for 5 seconds or more.
  • Wire harness or connector
  • Stop light switch assembly
  • Skid control ECU (brake booster with master cylinder assembly)
  • Rear combination light assembly LH
  • Rear combination light assembly RH
  • Rear light assembly LH*
  • Rear light assembly RH*
  • Center stop light set
  • Hybrid vehicle control ECU
  • Certification ECU (smart key ECU assembly)
  • Vehicle approaching speaker controller

Does not come on

VSC DTC

*: w/ Cornering Light

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

    Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): INITIALIZATION

  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (STP, STPO AND STP2 TERMINAL)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the A35 skid control ECU (brake booster with master cylinder assembly) connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-12 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less

A35-22 (STPO) - Body ground

Always

11 to 14 V

A35-37 (STP2) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-37 (STP2) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less

Result

Proceed to

All terminal voltages are normal.

A

Only STP2 terminal voltage abnormal.

B

Only STPO terminal voltage abnormal.

C

Only STP terminal voltage abnormal.

D

STPO terminal and STP terminal voltage abnormal.

E
B

GO TO STEP 5

C

GO TO STEP 9

D

GO TO STEP 10

E

GO TO STEP 18

A

2.

PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY)

(a) Reconnect the A35 skid control ECU (brake booster with master cylinder assembly) connector.

(b) Select the Active Test on the Techstream.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DATA LIST / ACTIVE TEST

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Stop Light Relay

Stop light control relay (Stop light switch assembly)

Relay ON/OFF

-

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Stop Light Relay

(c) According to the display on the Techstream, perform the Active Test and check the operation of the stop lights.

OK:

Stop lights turn on/off in accordance with the Active Test.

NG

GO TO STEP 4

OK

3.

RECONFIRM DTC

(a) Clear the DTCs.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

Chassis > ABS/VSC/TRAC > Clear DTCs

(b) Select the Active Test on the Techstream.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DATA LIST / ACTIVE TEST

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Stop Light Relay

Stop light control relay (Stop light switch assembly)

Relay ON/OFF

-

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Stop Light Relay

(c) According to the display on the Techstream, perform the Active Test.

(d) Check if the same DTC is output.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DTC CHECK / CLEAR

Chassis > ABS/VSC/TRAC > Trouble Codes

Result

Proceed to

DTC C1380 is output.

A

DTC C1380 is not output.

B
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

USE SIMULATION METHOD TO CHECK

4.

INSPECT BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

(a) Select the Active Test on the Techstream.

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (for HV Model): DATA LIST / ACTIVE TEST

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Stop Light Relay

Stop light control relay (Stop light switch assembly)

Relay ON/OFF

-

Chassis > ABS/VSC/TRAC > Active Test

Tester Display

Stop Light Relay

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A33-4 (ACC) - Body ground

Active Test is on

1.5 V or less

*a

Component with harness connected

(Stop Light Switch Assembly)
OK

REPLACE STOP LIGHT SWITCH ASSEMBLY

NG

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

5.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the A23 hybrid vehicle control ECU connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-37 (STP2) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-37 (STP2) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less
OK

REPLACE HYBRID VEHICLE CONTROL ECU

NG

6.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - SMART KEY ECU ASSEMBLY)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the K10 certification ECU (smart key ECU assembly) connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-37 (STP2) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-37 (STP2) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less
OK

REPLACE SMART KEY ECU ASSEMBLY

NG

7.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - STOP LIGHT SWITCH ASSEMBLY)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the A33 stop light switch assembly connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-37 (STP2) - Body ground

Always

1.5 V or less
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

8.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - STOP LIGHT SWITCH ASSEMBLY)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A35-37 (STP2) - A33-3 (L)

Always

Below 1 Ω

A35-37 (STP2) or A33-3 (L) - Body ground

Always

10 kΩ or higher
OK

REPLACE STOP LIGHT SWITCH ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

9.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - STOP LIGHT SWITCH ASSEMBLY)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(b) Disconnect the A33 stop light switch assembly connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A35-22 (STPO) - A33-4 (ACC)

Always

Below 1 Ω
OK

REPLACE STOP LIGHT SWITCH ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

10.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - REAR COMBINATION LIGHT ASSEMBLY LH)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the P10 rear combination light assembly LH connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-12 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less
OK

GO TO LIGHTING SYSTEM (REAR COMBINATION LIGHT ASSEMBLY LH (STOP LIGHT CIRCUIT))

w/ Cornering Light: Refer to "Left or right stop light (rear combination light assembly) does not illuminate" of problem symptoms table.

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model with Cornering Light): PROBLEM SYMPTOMS TABLE

w/o Cornering Light: Refer to "Left or right stop light does not illuminate" of problem symptoms table.

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model without Cornering Light): PROBLEM SYMPTOMS TABLE

NG

11.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - REAR COMBINATION LIGHT ASSEMBLY RH)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the P9 rear combination light assembly RH connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-12 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less

Result

Proceed to

OK

A

NG (w/o Cornering Light)

B

NG (w/ Cornering Light)

C
A

GO TO LIGHTING SYSTEM (REAR COMBINATION LIGHT ASSEMBLY RH (STOP LIGHT CIRCUIT))

w/ Cornering Light: Refer to "Left or right stop light (rear combination light assembly) does not illuminate" of problem symptoms table.

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model with Cornering Light): PROBLEM SYMPTOMS TABLE

w/o Cornering Light: Refer to "Left or right stop light does not illuminate" of problem symptoms table.

Click here 2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model without Cornering Light): PROBLEM SYMPTOMS TABLE

B

GO TO STEP 14

C

12.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - REAR LIGHT ASSEMBLY LH)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the P12 rear light assembly LH connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-12 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less
OK

Refer to "Left or right stop light (rear light assembly) does not illuminate" of problem symptoms table.

Click here GO TO LIGHTING SYSTEM (REAR LIGHT ASSEMBLY LH (STOP LIGHT CIRCUIT))

NG

13.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - REAR LIGHT ASSEMBLY RH)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the P11 rear light assembly RH connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-12 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less
OK

Refer to "Left or right stop light (rear light assembly) does not illuminate" of problem symptoms table.

Click here GO TO LIGHTING SYSTEM (REAR LIGHT ASSEMBLY RH (STOP LIGHT CIRCUIT))

NG

14.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - CENTER STOP LIGHT SET)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the K41 center stop light set connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-12 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less
OK

REPLACE CENTER STOP LIGHT SET

NG

15.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - VEHICLE APPROACHING SPEAKER CONTROLLER)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the G38 vehicle approaching speaker controller connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

11 to 14 V

A35-12 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

1.5 V or less
OK

REPLACE VEHICLE APPROACHING SPEAKER CONTROLLER

NG

16.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - STOP LIGHT SWITCH ASSEMBLY)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

(b) Disconnect the A33 stop light switch assembly connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A35-12 (STP) - Body ground

Always

1.5 V or less
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

17.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - STOP LIGHT SWITCH ASSEMBLY)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A33-1 (OUT) - A35-12 (STP)

Always

Below 1 Ω

A33-1 (OUT) or A35-12 (STP) - Body ground

Always

10 kΩ or higher
OK

REPLACE STOP LIGHT SWITCH ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

18.

CHECK STOP LIGHT SWITCH ASSEMBLY POWER SOURCE CIRCUIT

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

*a

Front view of wire harness connector

(to Stop Light Switch Assembly)

(b) Disconnect the A33 stop light switch assembly connector.

(c) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A33-7 (B) - Body ground

Always

11 to 14 V

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A33-2 (GND) - Body ground

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

19.

CHECK HARNESS AND CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - STOP LIGHT SWITCH ASSEMBLY)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A35-22 (STPO) or A33-4 (ACC) - Body ground

Always

10 kΩ or higher
OK

REPLACE STOP LIGHT SWITCH ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR