Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000002BT1L
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [03/2023 -           ]
Title: LIGHTING (EXT): LIGHTING SYSTEM: Back-up Light Circuit; 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2023 -        ]

Back-up Light Circuit

DESCRIPTION

for HV Model:

  • The hybrid vehicle control ECU controls the back-up lights via the BKUP LP relay.

for CVT (K121):

  • The ECM controls the back-up lights via the BKUP LP relay.

WIRING DIAGRAM

for HV Model

for CVT (K121)

CAUTION / NOTICE / HINT

NOTICE:

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

    for HV Model:Click here 2023 - 2025 MY Corolla Corolla HV [09/2022 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION

    for Gasoline Model:Click here 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION

  • When replacing the hybrid vehicle control ECU, update the ECU security key.*1

    Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: UPDATE ECU SECURITY KEY

  • When replacing the ECM, update the ECU security key.*2

    Click here 2023 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 -        ]; SETUP: WHEN REPLACING OR REMOVING/INSTALLING PARTS: UPDATE ECU SECURITY KEY

    • *1: for HV Model
    • *2: for CVT (K121)

PROCEDURE

1.

CONFIRM MODEL

(a) Choose the model to be inspected.

Result

Proceed to

for HV Model

A

for CVT (K121)

B

B

GO TO STEP 12

A

2.

READ VALUE USING GTS

(a) Turn the ignition switch to ON.

(b) Move the shift lever to R.

(c) Read the Data List according to the display on the GTS.

Body Electrical > Power Distribution Box > Data List

Tester Display

Measurement Item

Normal Condition

Reference Value

Diagnostic Note

Back-up Light Fuse Shut Off Status

Back-up light fuse shut off status

OFF or ON

OFF: Fuse has no shut off history

ON: Fuse has shut off history

-

Body Electrical > Power Distribution Box > Data List

Tester Display

Back-up Light Fuse Shut Off Status

OK:

The Data List value displays "OFF".

NG

GO TO STEP 9

OK

3.

READ VALUE USING GTS

(a) Read the Data List according to the display on the GTS.

Body Electrical > Power Distribution Box > Data List

Tester Display

Measurement Item

Normal Condition

Reference Value

Diagnostic Note

Back-up Light Input Signal

Back-up light input

OFF or ON

OFF: Shift lever in any position other than R

ON: Shift lever in R

-

Body Electrical > Power Distribution Box > Data List

Tester Display

Back-up Light Input Signal

OK:

Display changes according to shift lever operation.

NG

GO TO STEP 7

OK

4.

CHECK HARNESS AND CONNECTOR (POWER SOURCE - POWER DISTRIBUTION BOX ASSEMBLY)

(a) Disconnect the 8J power distribution box assembly connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

8J-1 - Body ground

Ignition switch off

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.

CHECK HARNESS AND CONNECTOR (REAR LIGHT ASSEMBLY - POWER DISTRIBUTION BOX ASSEMBLY)

(a) Disconnect the O110 rear light assembly LH connector.

(b) Disconnect the O109 rear light assembly RH connector.

(c) Disconnect the 8H power distribution box assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O110-1 (B) - 8H-13

Always

Below 1 Ω

O109-1 (B) - 8H-13

Always

Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.

CHECK HARNESS AND CONNECTOR (BAREAR LIGHT ASSEMBLY - BODY GROUND)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O110-2 (E) - Body ground

Always

Below 1 Ω

O109-2 (E) - Body ground

Always

Below 1 Ω

OK

REPLACE POWER DISTRIBUTION BOX ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - POWER DISTRIBUTION BOX ASSEMBLY)

(a) Disconnect the I3 hybrid vehicle control ECU connector.

(b) Disconnect the 8D power distribution box assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I3-24 (BL) - 8D-27

Always

Below 1 Ω

I3-24 (BL) or 8D-27 - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.

CHECK HYBRID VEHICLE CONTROL ECU (OUTPUT VOLTAGE)

*a

Component with harness connected

(Power Distribution Box Assembly)

(a) Connect the I3 hybrid vehicle control ECU connector.

(b) Connect the 8D power distribution box assembly connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

8D-27 - Body ground

Ignition switch ON, reverse (R) not selected

Below 1 V

8D-27 - Body ground

Ignition switch ON, reverse (R) selected

11 to 14 V

OK

REPLACE POWER DISTRIBUTION BOX ASSEMBLY

NG

REPLACE HYBRID VEHICLE CONTROL ECU

9.

CHECK REAR LIGHT ASSEMBLY LH

(a) Disconnect the O110 rear light assembly LH connector.

(b) Turn the ignition switch to ON.

(c) Move the shift lever to R.

(d) Read the Data List according to the display on the GTS.

Body Electrical > Power Distribution Box > Data List

Tester Display

Measurement Item

Normal Condition

Reference Value

Diagnostic Note

Back-up Light Fuse Shut Off Status

Back-up light fuse shut off status

OFF or ON

OFF: Fuse has no shut off history

ON: Fuse has shut off history

-

Body Electrical > Power Distribution Box > Data List

Tester Display

Back-up Light Fuse Shut Off Status

OK:

The Data List value displays "OFF".

OK

REPLACE REAR LIGHT ASSEMBLY LH

NG

10.

CHECK REAR LIGHT ASSEMBLY RH

(a) Disconnect the O109 rear light assembly RH connector.

(b) Turn the ignition switch to ON.

(c) Move the shift lever to R.

(d) Read the Data List according to the display on the GTS.

Body Electrical > Power Distribution Box > Data List

Tester Display

Measurement Item

Normal Condition

Reference Value

Diagnostic Note

Back-up Light Fuse Shut Off Status

Back-up light fuse shut off status

OFF or ON

OFF: Fuse has no shut off history

ON: Fuse has shut off history

-

Body Electrical > Power Distribution Box > Data List

Tester Display

Back-up Light Fuse Shut Off Status

OK:

The Data List value displays "OFF".

OK

REPLACE REAR LIGHT ASSEMBLY RH

NG

11.

CHECK HARNESS AND CONNECTOR (REAR LIGHT ASSEMBLY - POWER DISTRIBUTION BOX ASSEMBLY)

(a) Disconnect the 8H power distribution box assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O110-1 (B), O109-1 (B) or 8H-13 - Body ground

Always

10 kΩ or higher

OK

REPLACE POWER DISTRIBUTION BOX ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

12.

CHECK FOR DTC

(a) Check if SFI system DTCs are output.

Powertrain > Engine > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTCs are output

B

B

GO TO SFI SYSTEM

A

13.

CHECK HARNESS AND CONNECTOR (ECM - POWER DISTRIBUTION BOX ASSEMBLY)

(a) Disconnect the 8F power distribution box assembly connector.

(b) Disconnect the A178 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A178-82 (BL) - 8F-17

Always

Below 1 Ω

A178-82 (BL) or 8F-17 - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

14.

CHECK ECM (OUTPUT VOLTAGE)

*a

Component with harness connected

(Power Distribution Box Assembly)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

8F-17 - Body ground

Ignition switch ON, shift lever not in R

Below 1 V

8F-17 - Body ground

Ignition switch on (IG), shift lever in R

11 to 14 V

NG

REPLACE ECM

OK

15.

INSPECT POWER DISTRIBUTION BOX ASSEMBLY (OUTPUT VOLTAGE)

*a

Component with harness connected

(Power Distribution Box Assembly)

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

8H-13 - Body ground

Ignition switch ON, shift lever not in R

Below 1 V

8H-13 - Body ground

Ignition switch ON, shift lever in R

11 to 14 V

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR

NG

REPLACE POWER DISTRIBUTION BOX ASSEMBLY