Last Modified: 11-20-2023 6.11:8.1.0 Doc ID: RM100000001SISQ
Model Year Start: 2021 Model: Camry Prod Date Range: [10/2020 -           ]
Title: SEAT BELT: SEAT BELT WARNING SYSTEM: Rear Seat Belt Warning Light Malfunction; 2021 - 2024 MY Camry [10/2020 -        ]

Rear Seat Belt Warning Light Malfunction

DESCRIPTION

The main body ECU (multiplex network body ECU) detects whether either the rear doors are open or closed based on the courtesy light switch condition and then sends the rear door status signal to the combination meter assembly. The combination meter assembly detects the rear seat belt state. The rear seat belt warning light on the telltale light assembly illuminates, blinks or turns off in accordance with the rear door state, vehicle speed and rear seat belt state.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • The seat belt warning system uses the CAN communication system. First, confirm that there is no malfunction in the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure.

    Click here 2018 - 2024 MY Camry [03/2017 -        ]; SEAT BELT: SEAT BELT WARNING SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING

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

PROCEDURE

1.

READ VALUE USING TECHSTREAM (REAR DOOR COURTESY LIGHT SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Main Body > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

RR Door Courtesy SW

Rear door courtesy light switch RH

ON or OFF

ON: Rear door RH open

OFF: Rear door RH closed

-

RL Door Courtesy SW

Rear door courtesy light switch LH

ON or OFF

ON: Rear door LH open

OFF: Rear door LH closed

-

Body Electrical > Main Body > Data List

Tester Display

RR Door Courtesy SW

RL Door Courtesy SW

OK:

The Techstream display changes correctly in response to the rear door condition.

NG

GO TO LIGHTING SYSTEM

OK

2.

CHECK REAR SEAT BELT WARNING

(a) Check the rear seat belt warning function.

Click here 2021 - 2022 MY Camry [10/2020 - 08/2022]; SEAT BELT: SEAT BELT WARNING SYSTEM: ON-VEHICLE INSPECTION 2023 - 2024 MY Camry [08/2022 -        ]; SEAT BELT: SEAT BELT WARNING SYSTEM: ON-VEHICLE INSPECTION

*1

Rear Seat Belt Warning Light (Telltale Light)

*a

LH

*b

Center

*c

RH

Result

Proceed to

The rear seat belt warning lights operation is normal

A

The rear seat belt warning lights (all seats) do not operate normally

B

The rear seat belt warning light (RH) does not operate normally

C

The rear seat belt warning light (center) does not operate normally

D

The rear seat belt warning light (LH) does not operate normally

E

A

USE SIMULATION METHOD TO CHECK

C

GO TO STEP 6

D

GO TO STEP 10

E

GO TO STEP 14

B

3.

PERFORM ACTIVE TEST USING TECHSTREAM (REAR SEAT BELT WARNING LIGHT)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Combination Meter > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Rear Seat Belt Warning

Rear seat belt warning light

OFF/ON

-

Body Electrical > Combination Meter > Active Test

Tester Display

Rear Seat Belt Warning

Result

Proceed to

The rear seat belt warning light does not operate normally

A

The rear seat belt warning light operates normally

B

B

REPLACE COMBINATION METER ASSEMBLY

A

4.

CHECK HARNESS AND CONNECTOR (BATTERY - TELLTALE LIGHT ASSEMBLY)

(a) Disconnect the K36 telltale light assembly connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

K36-10 (IG+) - Body ground

Ignition switch ON

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.

CHECK HARNESS AND CONNECTOR (TELLTALE LIGHT ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Reconnect the K36 telltale light assembly connector.

(b) Disconnect the K21 combination meter assembly connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

K21-18 (RLMT) - Body ground

Ignition switch ON

11 to 14 V

K21-19 (RCMT) - Body ground

Ignition switch ON

11 to 14 V

K21-20 (RRMT) - Body ground

Ignition switch ON

11 to 14 V

OK

REPLACE COMBINATION METER ASSEMBLY

NG

REPLACE TELLTALE LIGHT ASSEMBLY

6.

READ VALUE USING TECHSTREAM (REAR SEAT BELT BUCKLE SWITCH (FOR RH))

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Combination Meter > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Rear Right Seat Buckle / Occupant Detection Warning Switch

Rear seat inner with center belt RH buckle signal

ON or OFF

OFF: Rear RH seat belt fastened

ON: Rear RH seat belt not fastened

-

Body Electrical > Combination Meter > Data List

Tester Display

Rear Right Seat Buckle / Occupant Detection Warning Switch

Result

Proceed to

ON or OFF does not appear on the tester screen according to the rear seat belt condition

A

ON or OFF appears on the tester screen according to the rear seat belt condition

B

B

GO TO STEP 8

A

7.

CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - REAR SEAT INNER WITH CENTER BELT ASSEMBLY RH - BODY GROUND)

(a) Disconnect the K21 combination meter assembly connector.

(b) Disconnect the R72 rear seat inner with center belt assembly RH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

K21-26 (RRSB) - R72-5

Always

Below 1 Ω

K21-26 (RRSB) or R72-5 - Body ground

Always

10 kΩ or higher

R72-4 - Body ground

Always

Below 1 Ω

OK

REPLACE REAR SEAT INNER WITH CENTER BELT ASSEMBLY RH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.

PERFORM ACTIVE TEST USING TECHSTREAM (REAR SEAT BELT WARNING LIGHT)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Combination Meter > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Rear Seat Belt Warning

Rear seat belt warning light

OFF/ON

-

Body Electrical > Combination Meter > Active Test

Tester Display

Rear Seat Belt Warning

Result

Proceed to

The rear seat belt warning light does not operate normally

A

The rear seat belt warning light operates normally

B

B

REPLACE COMBINATION METER ASSEMBLY

A

9.

CHECK HARNESS AND CONNECTOR (TELLTALE LIGHT ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the K21 combination meter assembly connector.

(b) Disconnect the K36 telltale light assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

K21-20 (RRMT) - K36-3 (RRID)

Always

Below 1 Ω

K21-20 (RRMT) or K36-3 (RRID) - Body ground

Always

10 kΩ or higher

OK

REPLACE TELLTALE LIGHT ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

10.

READ VALUE USING TECHSTREAM (REAR SEAT BELT BUCKLE SWITCH (FOR CENTER))

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Combination Meter > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Rear Center Seat Buckle / Occupant Detection Warning Switch

Rear seat inner with center belt LH (for center) buckle signal

ON or OFF

OFF: Rear LH seat belt (for center) fastened

ON: Rear LH seat belt (for center) not fastened

-

Body Electrical > Combination Meter > Data List

Tester Display

Rear Center Seat Buckle / Occupant Detection Warning Switch

Result

Proceed to

ON or OFF does not appear on the tester screen according to the rear seat belt condition

A

ON or OFF appears on the tester screen according to the rear seat belt condition

B

B

GO TO STEP 12

A

11.

CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH (FOR CENTER) - BODY GROUND)

(a) Disconnect the K21 combination meter assembly connector.

(b) Disconnect the R74 rear seat inner with center belt assembly LH (for center) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

K21-25 (RCSB) - R74-1

Always

Below 1 Ω

K21-25 (RCSB) or R74-1 - Body ground

Always

10 kΩ or higher

R74-2 - Body ground

Always

Below 1 Ω

OK

REPLACE REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

12.

PERFORM ACTIVE TEST USING TECHSTREAM (REAR SEAT BELT WARNING LIGHT)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Combination Meter > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Rear Seat Belt Warning

Rear seat belt warning light

OFF/ON

-

Body Electrical > Combination Meter > Active Test

Tester Display

Rear Seat Belt Warning

Result

Proceed to

The rear seat belt warning light does not operate normally

A

The rear seat belt warning light operates normally

B

B

REPLACE COMBINATION METER ASSEMBLY

A

13.

CHECK HARNESS AND CONNECTOR (TELLTALE LIGHT ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the K21 combination meter assembly connector.

(b) Disconnect the K36 telltale light assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

K21-19 (RCMT) - K36-2 (RCID)

Always

Below 1 Ω

K21-19 (RCMT) or K36-2 (RCID) - Body ground

Always

10 kΩ or higher

OK

REPLACE TELLTALE LIGHT ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.

READ VALUE USING TECHSTREAM (REAR SEAT BELT BUCKLE SWITCH (FOR LH))

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Combination Meter > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Rear Left Seat Buckle / Occupant Detection Warning Switch

Rear seat inner with center belt LH (for LH) buckle signal

ON or OFF

OFF: Rear LH seat belt (for LH) fastened

ON: Rear LH seat belt (for LH) not fastened

-

Body Electrical > Combination Meter > Data List

Tester Display

Rear Left Seat Buckle / Occupant Detection Warning Switch

Result

Proceed to

ON or OFF does not appear on the tester screen according to the rear seat belt condition

A

ON or OFF appears on the tester screen according to the rear seat belt condition

B

B

GO TO STEP 16

A

15.

CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH (FOR LH) - BODY GROUND)

(a) Disconnect the K21 combination meter assembly connector.

(b) Disconnect the R73 rear seat inner with center belt assembly LH (for LH) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

K21-24 (RLSB) - R73-5

Always

Below 1 Ω

K21-24 (RLSB) or R73-5 - Body ground

Always

10 kΩ or higher

R73-4 - Body ground

Always

Below 1 Ω

OK

REPLACE REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

16.

PERFORM ACTIVE TEST USING TECHSTREAM (REAR SEAT BELT WARNING LIGHT)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.

(e) Perform the Active Test according to the display on the Techstream.

Body Electrical > Combination Meter > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Rear Seat Belt Warning

Rear seat belt warning light

OFF/ON

-

Body Electrical > Combination Meter > Active Test

Tester Display

Rear Seat Belt Warning

Result

Proceed to

The rear seat belt warning light does not operate normally

A

The rear seat belt warning light operates normally

B

B

REPLACE COMBINATION METER ASSEMBLY

A

17.

CHECK HARNESS AND CONNECTOR (TELLTALE LIGHT ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the K21 combination meter assembly connector.

(b) Disconnect the K36 telltale light assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

K21-18 (RLMT) - K36-1 (RLID)

Always

Below 1 Ω

K21-18 (RLMT) or K36-1 (RLID) - Body ground

Always

10 kΩ or higher

OK

REPLACE TELLTALE LIGHT ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR