Seat belt warning system
Parts location System information Troubleshooting Circuit diagnosis Removal / installation
SEAT BELT
SEAT BELT WARNING SYSTEM
FUNCTION INSPECTION
1. Inspection of the driver’s seat belt warning light
(1) Turn the ignition switch to ON.
(2) Sitting in the driver’s seat, without the seat belt tongue plate inserted in the buckle, check that the driver’s seat belt warning light in the combination meter ASSY blinks.
(3) Sitting in the driver’s seat, insert the seat belt tongue plate in the buckle, and check that the driver’s seat belt warning light in the combination meter ASSY turns off.
2. Inspection of the passenger’s seat belt warning light
(1) Turn the ignition switch to ON.
(2) Sitting in the passenger’s seat, without the seat belt tongue plate inserted in the buckle, check that the passenger’s seat belt warning light in the clock ASSY blinks.
(3) Sitting in the passenger’s seat, insert the seat belt tongue plate in the buckle, and check that the passenger’s seat belt warning light in the clock ASSY turns off.
3. Inspection of the seat belt warning buzzer
NOTE:
Check that the settings for the seat belt warning buzzer customized with the SSM3 are ON.
(1) Lift up the vehicle.
(2) Start the engine.
(3) With the seat belt tongue plate not inserted in the buckle, drive the vehicle at approx. 20 km/h or above. In this condition, check that the buzzer in the combination meter ASSY sounds at 1.2-second intervals for 30 seconds.
(4) When 30 seconds have passed after the buzzer starts sounding, check that the interval changes, and the buzzer continues to sound at 0.4-second intervals for 90 seconds.
(5) Check that the buzzer stops sounding 120 seconds after it first started to sound.
(6) After the buzzer stops sounding, turn the ignition switch to OFF, and restart the engine. With the seat belt tongue plate not inserted in the buckle, drive the vehicle at approx. 20 km/h or above, and check that the buzzer sounds again.
(7) After the buzzer stops sounding, insert the seat belt tongue plate in the buckle, drive the vehicle at approx. 20 km/h or above, and unfasten the seat belt. Check that the buzzer sounds again.
(8) After the buzzer stops sounding, change the shift position to R, and then to D. With the seat belt tongue plate not inserted in the buckle, drive the vehicle at approx. 20 km/h or above, and check that the buzzer sounds again.
PARTS LOCATION
SYMPTOM TABLE
| Symptoms |
Inspection items |
Reference pages |
|---|---|---|
| Driver’s seat belt warning light does not operate |
Refer to the troubleshooting flowchart “Driver’s seat belt warning light does not operate” |
 |
| Passenger’s seat belt warning light does not operate |
Refer to the troubleshooting flowchart “Passenger’s seat belt warning light does not operate” |
|
| Faulty seat belt warning buzzer |
Confirmation of customized settings with SSM3 |
- |
| Replacement of combination meter ASSY |
|
HOW TO TROUBLESHOOT
1.
Bring in the car
Next▼
2.
Interview and phenomenon check
(1) Perform the interview and phenomenon check (Refer to )
)Next▼
3.
Communication function inspection of the CAN communication system
(1) Check CAN communication system. (Refer to )
)
Result
| Result |
Go to |
|---|---|
| If the CAN communication system is functioning properly, [there is no "CAN communication error, ECM communication error / lost communication" diagnostic code output.] |
A |
| If the CAN communication system is not functioning properly, [there is a "CAN communication error, ECM communication error / lost communication" diagnostic code output.] |
B |
B
>See the CAN communication system troubleshooting flowchart
A▼
4.
Symptom table
(1) Check the symptom table. (Refer to )
)
B
>Go to Step 6.
A▼
5.
Based on the trouble phenomenon, perform troubleshooting following the steps below.
(1) Functional inspection (refer to )
)(2) ECM terminal matrix (Refer to )
)(3) [Current Data Display & Save] / [System Operation Check Mode] (Refer to )
)(4) Unit inspection
Next▼
6.
Adjustment, repair, or replacement
Next▼
7.
Confirmation test
Next▼
Complete
CHECK LIST FOR INTERVIEW
CIRCUIT FIGURE
ECM TERMINAL ARRANGEMENT
1. Combination meter ASSY
(1) Inspect combination meter ASSY
(a) Disconnect connector D7 of the combination meter ASSY.
(b) Measure the voltage and resistance between terminals.
| Terminal No. (Terminal symbol) |
Terminal description |
Inspection conditions |
Standard value |
|---|---|---|---|
| D7-1 (+B) ←→ Chassis ground |
Battery power supply |
Always |
11 to 14 V |
| D7-2 (IG+) ←→ Chassis ground |
IG power supply |
IG OFF → IG ON |
1 V or less → 11 to 14 V |
| D7-13 (P/SB) ←→ Chassis ground |
Passenger’s seat belt warning light lighting signal |
IG ON, passenger’s seat occupied, and seat belt buckled → not buckled |
1 V or less → 11 to 14 V |
| D7-20 (GND) ←→ Chassis ground |
Ground |
Always |
Less than 1 Ω |
| D7-37 (DBKL) ←→ Chassis ground |
Driver’s inner belt buckle switch signal |
IG ON, driver’s seat belt buckled → Not buckled |
10 kΩ or more → less than 1 Ω |
| D7-38 (PBKL) ←→ Chassis ground |
Passenger’s inner belt buckle switch signal |
IG ON, passenger’s seat occupied, and seat belt buckled → not buckled |
10 kΩ or more → less than 1 Ω |
| D7-40 (GND) ←→ Chassis ground |
Ground |
Always |
Less than 1 Ω |
(c) Connect the connector D7 of the combination meter ASSY.
(d) Measure the voltage between the terminals.
| Terminal No. (Terminal symbol) |
Terminal description |
Inspection conditions |
Standard value |
|---|---|---|---|
| D7-13 (P/SB) ←→ Chassis ground |
Passenger’s seat belt warning light lighting signal |
IG ON, passenger’s seat occupied, and seat belt buckled → not buckled |
1 V or less → 11 to 14 V |
[CURRENT DATA DISPLAY & SAVE]/[SYSTEM OPERATION CHECK MODE]
1. Inspection with SSM3
(1) Data monitor
(a) On the SSM3, navigate to the [Current Data Display & Save] display, and check the computer data.
Criteria
SSM3 screen: [Each System Check] → [Integ. unit mode] → [Work Support]→ [System Operation Check Mode]
| Item Name |
Description/display range |
Normal value |
Remarks |
|---|---|---|---|
| [P-Seatbelt Buckle SW] |
Passenger’s seat belt buckle status Display range: OFF/ON |
OFF: Passenger’s seat belt is buckled. ON: Passenger’s seat belt is not buckled. |
Passenger’s seat occupied |
(2) System Operation Check Mode
(a) Using SSM3, display the [System Operation Check Mode] screen according to the screen instructions and perform inspection.
Criteria
SSM3 screen: [Each System Check]→ [Integ. unit mode]→ [Work Support]→ [System Operation Check Mode]
| Item Name |
Item description |
Drive |
|---|---|---|
| [Driver side seat belt warning] |
Turns on the driver’s seat belt warning light. |
Driver’s seat belt |
| [P seat seat-belt warning] |
Turns on the passenger’s seat belt warning light. |
Passenger’s seat belt |
| Driver’s seat belt warning light does not operate |
|---|
Circuit description
During IG ON, the combination meter ASSY detects the status of the driver’s seat front seat inner belt ASSY.
According to the vehicle speed and the status of the front seat inner belt ASSY RH, the combination meter makes the seat belt warning light (in the combination meter ASSY) turn on, blink, or turn off.
Circuit figure
Inspection steps
1.
Implementation of the SSM3 System Operation Support (Driver’s seat belt warning)
(1) On the SSM3, navigate to the [System Operation Support] display, and check the displayed data. (Refer to )
)
Criteria
: The System Operation Support can be performed properly.
SSM3 display: [Each System Check] → [Combination meter] → [Work Support] → [System Operation Check Mode] → [Lamp check]
| Item Name |
Contents of testing |
Criteria |
|---|---|---|
| [Driver side seat belt warning] |
Turn on (blinking) and turn off the driver’s seat belt warning light. |
The driver’s seat belt warning light turns on (blinks) or turns off. |
NG
>Replacement of the combination meter ASSY (refer to )
)OK▼
2.
Unit inspection of the front seat inner belt ASSY (for Driver)
(1) Perform the unit inspection for the front seat inner belt ASSY (for Driver). (Refer to )
)NG
>Replacement of the front seat inner belt ASSY (for Driver) (Refer to )
)OK▼
3.
Inspection of wiring harnesses and connectors (front seat inner belt ASSY (for Driver) - combination meter ASSY and chassis ground)
NOTE:
For inspection procedures and precautions, refer to .
.(1) Disconnect the connector H19*1 or G3*2 of the front seat inner belt ASSY (for Driver).
(2) Disconnect connector D7 of the combination meter ASSY.
(3) Measure the resistance between the terminals. (For terminal arrangement, refer to .)
.)
Resistance
| Inspection terminals |
Inspection conditions |
Standard value |
|---|---|---|
| D7-37 - (DBKL) - H19 -1*1 |
Always |
Less than 1 Ω |
| H19-1 - Chassis ground*1 |
Always |
10 kΩ or more |
| H19-2 - Chassis ground*1 |
Always |
Less than 1 Ω |
| D7-37 (DBKL) - G3-1*2 |
Always |
Less than 1 Ω |
| G3-1 - Chassis ground*2 |
Always |
10 kΩ or more |
| G3-2 - Chassis ground*2 |
Always |
Less than 1 Ω |
*1 For LHD
*2 For RHD
NG
>Repair or replacement of wiring harness or connector
OK▼
Replacement of the combination meter ASSY (refer to )
)| Passenger’s seat belt warning light does not operate |
|---|
Circuit description
During IG ON and when the passenger’s seat is occupied, the combination meter ASSY detects the status of the front seat inner belt ASSY. If the tongue plate is not inserted in the buckle, the combination meter ASSY makes the passenger’s seat belt warning light in the clock ASSY blink, and when the tongue plate is inserted, makes it turn off.
Circuit figure
Inspection steps
NOTE:
Before performing the troubleshooting, check the fuse of this circuit.
1.
SSM3 [Current Data Display & Save] (P-Seatbelt Buckle SW)
(1) Using SSM3, navigate to [Current Data Display & Save] for the combination meter ASSY. (Refer to )
)
SSM3 display: [Each System Check] → [Combination meter] → [Current Data Display & Save]
| Item Name |
Description/display range |
Normal value |
Remarks |
|---|---|---|---|
| [P-Seatbelt Buckle SW] |
Passenger’s seat buckle SW state Display range: [ON]/[OFF] |
ON: Passenger’s seat belt buckle switch unbuckled OFF: Passenger’s seat belt buckle switch buckled |
It matches the passenger’s seat occupation status. |
Criteria
: The SSM3 display changes according to the status for the passenger’s seat belt that is “buckled or unbuckled.”
NG
> Go to Step 5.
OK▼
2.
Performing the SSM3 system operation check mode (passenger’s seat belt warning light)
(1) Using the SSM3, perform the System Operation Inspection Mode for the combination meter ASSY. (Refer to )
)
SSM3 display: [Each System Check] → [Combination meter] → [Work Support] → [System Operation Check Mode] → [Lamp check]
| Item Name |
Item description |
Drive |
|---|---|---|
| [P seat seat-belt warning] |
Turns on the passenger’s seat belt warning light. |
Passenger’s seat belt |
Criteria
: The passenger’s seat belt warning light in the clock ASSY lights up according to SSM3 operation.
NG
> Go to Step 3.
OK▼
Replacement of the combination meter ASSY (refer to )
)3.
Unit inspection for the clock ASSY
(1) Remove the clock ASSY. (Refer to )
)
(2) Check the lighting condition of the passenger’s seat belt warning light when the battery is connected to each terminal of the connector.
| Battery connection |
Criteria |
|---|---|
| Battery positive → 10 Battery ground → 6 |
The passenger’s seat belt warning light turns on. |
Captions in illustration
| *a |
Connector not connected (Clock ASSY) |
NG
>Replacement of the clock ASSY (Refer to )
)OK▼
4.
Inspection of the wiring harnesses and the connectors (clock ASSY - combination meter ASSY and battery)
NOTE:
For inspection procedures and precautions, refer to .
.(1) Disconnect the connector D18 of the clock ASSY.
(2) Disconnect connector D7 of the combination meter ASSY.
(3) Measure the resistance between connector terminals on the vehicle wire harness side.
NG
>Repair or replacement of wiring harness or connector
OK▼
Replacement of the combination meter ASSY (refer to )
)5.
Unit inspection for the front seat ASSY (for Front Passenger) (Seating Switch)
(1) Perform the unit inspection for the front seat ASSY (for Front Passenger) (Seating Switch). (Refer to )
)NG
>Replacement of the front seat ASSY (for Front Passenger) (Seating Switch) (Refer to )
)OK▼
6.
Unit inspection for the front seat inner belt ASSY (for Front Passenger)
(1) Perform the unit inspection for the front seat inner belt ASSY (for Front Passenger). (Refer to )
)NG
>Replacement of the front seat inner belt ASSY (for Front Passenger) (Refer to )
)OK▼
7.
Inspection of wiring harnesses and connectors (front seat inner belt ASSY (for Front Passenger) - combination meter ASSY and chassis ground)
NOTE:
For inspection procedures and precautions, refer to .
.(1) Disconnect the connector G3*1 or H19*2 of the front seat inner belt ASSY (for Front Passenger).
(2) Disconnect connector D7 of the combination meter ASSY.
(3) Measure the resistance between connector terminals on the vehicle wire harness side.
Resistance
*1 For LHD
*2 For RHD| Inspection terminals |
Inspection conditions |
Standard value |
|---|---|---|
| D7-37 - (DBKL) - G3 -1*1 |
Always |
Less than 1 Ω |
| G3-1 - Chassis ground*1 |
Always |
10 kΩ or more |
| G3-2 - Chassis ground*1 |
Always |
Less than 1 Ω |
| H19-1 - D7-38*2 |
Always |
Less than 1 Ω |
| H19-1 - Chassis ground*2 |
Always |
10 kΩ or more |
| H19-2 - Chassis ground*2 |
Always |
Less than 1 Ω |
NG
>Repair or replacement of wiring harness or connector
OK▼
Replacement of the combination meter ASSY (refer to )
)