Toyota Prius: Seat Belt Warning System (w/ Occupant Classification System)

• Precaution
• Parts Location
• System Diagram
• System Description
• How To Proceed With Troubleshooting
• Operation Check
• Customize Parameters
• Problem Symptoms Table
• Terminals Of Ecu
• Diagnosis System
• Data List / Active Test
• Driver Side Seat Belt Warning Light does not Operate
• Front Passenger Side Seat Belt Warning Light does not Operate
• Rear Seat Belt Warning Light Malfunction

Precaution

PRECAUTION

PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE (-) AUXILIARY BATTERY TERMINAL

NOTICE:

After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.

Click here

HINT:

When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

Click here

Parts Location

PARTS LOCATION

ILLUSTRATION

*1

NO. 2 SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

-

-

ILLUSTRATION

*1	MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)	*2	POWER DISTRIBUTION BOX ASSEMBLY
*3	HYBRID Toyota Prius Vehicle CONTROL ECU	*4	COMBINATION METER ASSEMBLY - SEAT BELT WARNING BUZZER
*5	FRONT SEAT BELT WARNING LIGHT	*6	REAR SEAT BELT WARNING LIGHT
*7	AIRBAG ECU ASSEMBLY	*8	DLC3

ILLUSTRATION

*1	FRONT SEAT INNER BELT ASSEMBLY LH	*2	FRONT SEAT INNER BELT ASSEMBLY RH
*3	FRONT SEAT ADJUSTER ASSEMBLY RH - FRONT OCCUPANT CLASSIFICATION SENSOR LH - REAR OCCUPANT CLASSIFICATION SENSOR LH	-	-

ILLUSTRATION

*1	REAR DOOR LOCK WITH MOTOR ASSEMBLY RH - DOOR COURTESY SWITCH	*2	REAR DOOR LOCK WITH MOTOR ASSEMBLY LH - DOOR COURTESY SWITCH
*3	REAR SEAT INNER BELT ASSEMBLY RH	*4	REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH

System Diagram

SYSTEM DIAGRAM

Communication Table

Sender	Receiver	Signal	Communication Method
Airbag ECU assembly	Combination meter assembly	Front seat inner belt assembly RH buckle switch Occupant detection signal (for passenger side)	CAN
Main body ECU (Multiplex network body ECU)	Combination meter assembly	Rear seat inner belt buckle switch (LH/RH/Center) Rear door courtesy light switch signal (LH/RH)
No. 2 skid control ECU (brake actuator assembly)	Combination meter assembly	Toyota Prius Vehicle speed Parking brake switch
Hybrid vehicle control ECU	Combination meter assembly	Shift position
Power distribution box assembly	Main body ECU (multiplex network body ECU)	Rear seat inner belt buckle switch (LH/RH/Center)	CXPI

System Description

SYSTEM DESCRIPTION

SEAT BELT WARNING SYSTEM DESCRIPTION

(a) Seat belt warning light operation for driver seat belt:

The seat belt warning light on the combination meter assembly illuminates, blinks or turns off in accordance with the driver seat belt state, vehicle speed, shift lever position and parking brake state.

(b) Seat belt warning light operation for front passenger seat belt:

The seat belt warning light on the combination meter assembly illuminates, blinks or turns off in accordance with whether the front passenger seat is occupied, the front passenger seat belt state, Toyota Prius vehicle speed, shift lever position and parking brake state.

(c) Seat belt warning light operation for rear seat belt:

The rear seat belt warning light on the combination meter assembly illuminates, blinks or turns off in accordance with the rear door state, rear seat belt state, vehicle speed, shift lever position and parking brake state.

(d) Seat belt warning buzzer operation for front seat belt:

After turning the ignition switch to ON, if the driver seat belt is not fastened within 1.8 seconds, the seat belt warning buzzer in the combination meter assembly will sound at an interval of 1.2 seconds for 6 seconds.

When the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or more with the front passenger seat occupied and the driver or front passenger seat belt not fastened, the seat belt warning buzzer in the combination meter assembly sounds once.

When 18 seconds have passed after the buzzer sounded, the seat belt warning buzzer in the combination meter assembly will sound at an interval of 1.2 seconds for 6 seconds.

After that, the seat belt warning buzzer in the combination meter assembly will sound at an interval of 0.4 seconds for 100 seconds.

(e) Seat belt warning buzzer operation for rear seat belt:

When the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or more with a rear seat belt not fastened, the seat belt warning buzzer in the combination meter assembly sounds once.

When 18 seconds have passed after the buzzer sounded, the seat belt warning buzzer in the combination meter assembly will sound at an interval of 1.2 seconds for 6 seconds.

After that, the seat belt warning buzzer in the combination meter assembly will sound at an interval of 0.4 seconds for 66 seconds.

FUNCTION OF MAIN COMPONENTS

Component	Function
Front seat inner belt assembly LH	Informs the combination meter assembly of the driver seat belt condition (fastened or unfastened).
Front seat inner belt assembly RH	Informs the airbag ECU assembly of front passenger seat belt condition (fastened or unfastened).
Front occupant classification sensor LH (Front seat adjuster assembly RH) Rear occupant classification sensor LH (Front seat adjuster assembly RH)	Informs the airbag ECU assembly of the front passenger seat condition (occupied or unoccupied).
Combination meter assembly	Illuminates, blinks or turns off the seat belt warning light. Illuminates, blinks or turns off the rear seat belt warning light. Sounds the seat belt warning buzzer.
Rear seat inner belt assembly RH Rear seat inner with center belt assembly LH	Sends the rear seat belt buckle switch signal to the power distribution box assembly.
Rear door lock with motor assembly LH Rear door lock with motor assembly RH	Sends the rear door courtesy switch signal to the power distribution box assembly.
Main body ECU (multiplex network body ECU)	Sends the rear seat belt buckle switch signal and rear door courtesy light switch signal to the combination meter assembly via CAN communication.
Power distribution box assembly	Sends the rear seat belt buckle switch signal to the main body ECU (multiplex network body ECU) via CXPI communication.
No. 2 skid control ECU (brake actuator assembly)	Sends the Toyota Prius vehicle speed signal to the combination meter assembly via CAN communication. Sends the parking brake switch signal to the combination meter assembly via CAN communication.
Hybrid vehicle control ECU	Sends the shift position signal to the combination meter assembly via CAN communication.
Airbag ECU assembly	Sends the front passenger seat belt buckle switch signal and occupant detection signal to the combination meter assembly via CAN communication.

How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT

PROCEDURE

1.	Toyota Prius Vehicle BROUGHT TO WORKSHOP

NEXT

2.	CUSTOMER PROBLEM ANALYSIS

(a) Interview the customer to confirm the problem.

Click here

NEXT

3.

PRE-CHECK

(a) Measure the auxiliary battery voltage with the ignition switch off.

Standard Voltage:

11 to 14 V

If the voltage is below 11 V, recharge or replace the auxiliary battery before proceeding to the next step.

(b) Check the fuses and relays.

(c) Check the connector connections and terminals to make sure that there are no abnormalities such as loose connections, deformation, etc.

NEXT

4.	CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM*

(a) Using the GTS, check for CAN communication system DTCs.

for HEV Model: Click here

for PHEV Model: Click here

Result	Proceed to
CAN DTCs are not output	A
CAN DTCs are output	B

B

GO TO CAN COMMUNICATION SYSTEM for HEV Model: Click here for PHEV Model: Click here

A

5.	CHECK COMMUNICATION FUNCTION OF CXPI COMMUNICATION SYSTEM*

(a) Using the GTS, check for CXPI communication system DTCs.

Click here

Result	Proceed to
CXPI DTCs are not output	A
CXPI DTCs are output	B

B

GO TO CXPI COMMUNICATION SYSTEM

A

6.	CHECK COMBINATION METER ASSEMBLY

(a) Check the operation of the speedometer, shift indicator and brake warning light on the combination meter assembly.

OK:

The speedometer, shift indicator and brake warning light on the combination meter assembly operate normally.

NG

GO TO METER / GAUGE SYSTEM

OK

7.	PROBLEM SYMPTOMS TABLE

(a) Refer to Problem Symptoms Table.

Click here

Result	Proceed to
Fault is not listed in Problem Symptoms Table	A
Fault is listed in Problem Symptoms Table	B

B

GO TO STEP 9

A

8.	OVERALL ANALYSIS AND TROUBLESHOOTING*

(a) Data List / Active Test

Click here

(b) Terminals of ECU

Click here

(c) Inspection

NEXT

9.	REPAIR OR REPLACE

NEXT

10.	CONFIRMATION TEST

NEXT

END

Operation Check

OPERATION CHECK

HINT:

The seat belt warning light (in the combination meter assembly) is for both the driver seat and the passenger seat.

INSPECT DRIVER SEAT BELT WARNING LIGHT

(a) Turn the ignition switch off.

(b) Turn the ignition switch to ON.

(c) When the driver seat belt is not fastened, check that the seat belt warning light on the combination meter assembly blinks for 6 seconds.

Check that the seat belt warning light on the combination meter assembly changes from blinking to turns off.

(d) Lift the Toyota Prius vehicle.

Click here

(e) Turn the ignition switch to ON (READY).

(f) Check the status of the seat belt warning light (in the combination meter assembly) under the conditions below.

(1) Check that the seat belt warning light (in the combination meter assembly) blinks when the driver seat belt is unfastened, the shift position is not in P and the parking brake is released.

(2) Check that the seat belt warning light (in the combination meter assembly) blinks when the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or higher with the driver seat belt unfastened.

Check that after 106 seconds, the seat belt warning light (in the combination meter assembly) changes from blinking to on.

(3) Check that the seat belt warning light (in the combination meter assembly) changes to on when the seat belt warning light (in the combination meter assembly) is blinking, the Toyota Prius vehicle speed is 1.75 km/h (1 mph) or less and the shift position is changed to P.

(4) Check that the seat belt warning light (in the combination meter assembly) changes to on when the seat belt warning light (in the combination meter assembly) is blinking, the vehicle speed is 1.75 km/h (1 mph) or less and the parking brake is not released.

(5) Check that the seat belt warning light (in the combination meter assembly) turns off when the driver seat belt is fastened with the seat belt warning light (in the combination meter assembly) on or blinking.

INSPECT FRONT PASSENGER SEAT BELT WARNING LIGHT

HINT:

The seat belt warning light on the combination meter assembly is used for both the driver seat and front passenger seat.

(a) Turn the ignition switch to ON.

(b) Check that the seat belt warning light (in the combination meter assembly) turns on with a passenger seated in the passenger seat, the passenger seat belt unfastened and under the following conditions.

(1) Change the shift position to P.

(2) The parking brake is not released.

(c) Fasten the driver seat belt.

(d) Lift the Toyota Prius vehicle.

Click here

(e) Turn the ignition switch to ON (READY).

(f) Place a weight of 20 kg (44.1 lb) on the front passenger seat.

NOTICE:

When placing the load on the passenger seat, do not let it touch the seatback.

(g) Check the status of the seat belt warning light (in the combination meter assembly) under the conditions below.

(1) Check that the seat belt warning light (in the combination meter assembly) blinks when the passenger seat belt is unfastened, the shift position is not in P and the parking brake is released.

(2) Check that the seat belt warning light (in the combination meter assembly) blinks when the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or higher with the passenger seat belt unfastened.

Check that after 106 seconds, the seat belt warning light (in the combination meter assembly) changes from blinking to on.

(3) Check that the seat belt warning light (in the combination meter assembly) changes to on when the seat belt warning light (in the combination meter assembly) is blinking, the Toyota Prius vehicle speed is 1.75 km/h (1 mph) or less and the shift position is changed to P.

(4) Check that the seat belt warning light (in the combination meter assembly) changes to on when the seat belt warning light (in the combination meter assembly) is blinking, the vehicle speed is 1.75 km/h (1 mph) or less and the parking brake is not released.

(5) Check that the seat belt warning light (in the combination meter assembly) turns off when the passenger seat belt is fastened with the seat belt warning light (in the combination meter assembly) on or blinking.

INSPECT REAR SEAT BELT WARNING LIGHT

(a) Turn the ignition switch off.

*1	Combination Meter Assembly (Rear Seat Belt Warning Light )
*a	LH
*b	Center
*c	RH

(b) Unfasten the rear seat belt.

(c) Turn the ignition switch to ON.

(d) Check that the rear seat belt warning light (in the combination meter assembly) turns on.

(e) Check that the rear seat belt warning light turns on for approximately 66 seconds and then turns off.

(f) Fasten the rear seat belt.

(g) With the rear seat belt warning light off, check that the rear seat belt warning light in the combination meter assembly turns on again when the rear seat belt is unfastened.

INSPECT DRIVER SEAT BELT WARNING BUZZER

HINT:

Using the GTS, check that the customization setting for the seat belt warning buzzer (in the combination meter assembly) is on.

Click here

(a) Turn the ignition switch off.

(b) Turn the ignition switch to ON.

(c) After turning the ignition switch to ON, wait for approximately 1.8 seconds with the driver seat belt not fastened check that the seat belt warning buzzer in the combination meter assembly sounds at an interval of 1.2 seconds for 6 seconds.

(d) Lift the Toyota Prius vehicle.

Click here

(e) Turn the ignition switch to ON (READY).

(f) Check that the seat belt warning buzzer (in the combination meter assembly) sounds once when the vehicle is driven at approximately 20 km/h (12 mph) or higher with the seat belt unfastened.

(g) After 18 seconds have passed after the buzzer sounds once, check that the seat belt warning buzzer (in the combination meter assembly) sounds intermittently at 1.2-second intervals for 6 seconds.

(h) After the buzzer has sounded intermittently at 1.2-second intervals for 6 seconds, check that the interval changes and the buzzer sounds intermittently at 0.4-second intervals for 100 seconds.

(i) When 106 seconds have passed after the buzzer started sounding intermittently, check that the seat belt warning buzzer (in the combination meter assembly) stops.

(j) After the seat belt warning buzzer (in the combination meter assembly) stops, check that the buzzer sounds once and then once again sounds intermittently when the seat belt is fastened and then unfastened again, and then the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or higher.

(k) Check that the seat belt warning buzzer (in the combination meter assembly) stops when the shift position is changed to R while the seat belt warning buzzer (in the combination meter assembly) is sounding.

Check that the buzzer once again sounds intermittently when the shift position is changed to D again and the Toyota Prius vehicle is driven at approximately 5 km/h (3 mph) or higher with the seat belt unfastened.

INSPECT FRONT PASSENGER SEAT BELT WARNING BUZZER

HINT:

Using the GTS, check that the customization setting for the seat belt warning buzzer (in the combination meter assembly) is on.

Click here

(a) Lift the Toyota Prius vehicle.

Click here

(b) Fasten the driver seat belt.

(c) Turn the ignition switch to ON (READY).

(d) Place a weight of 20 kg (44.1 lb) on the front passenger seat.

NOTICE:

When placing the load on the passenger seat, do not let it touch the seatback.

(e) Check that the seat belt warning buzzer (in the combination meter assembly) sounds once when the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or higher with the seat belt unfastened.

(f) After 18 seconds have passed after the buzzer sounds once, check that the seat belt warning buzzer (in the combination meter assembly) sounds intermittently at 1.2-second intervals for 6 seconds.

(g) After the buzzer has sounded intermittently at 1.2-second intervals for 6 seconds, check that the interval changes and the buzzer sounds intermittently at 0.4-second intervals for 100 seconds.

(h) When 106 seconds have passed after the buzzer started sounding intermittently, check that the seat belt warning buzzer (in the combination meter assembly) stops.

(i) After the seat belt warning buzzer (in the combination meter assembly) stops, check that the buzzer sounds once and then once again sounds intermittently when the seat belt is fastened and then unfastened again, and then the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or higher.

(j) Check that the seat belt warning buzzer (in the combination meter assembly) stops when the shift position is changed to R while the seat belt warning buzzer (in the combination meter assembly) is sounding.

Check that the buzzer once again sounds intermittently when the shift position is changed to D again and the Toyota Prius vehicle is driven at approximately 5 km/h (3 mph) or higher with the seat belt unfastened.

INSPECT REAR SEAT BELT WARNING BUZZER

HINT:

The seat belt warning buzzer can be customized. Make sure that this function is ON.

Click here

(a) Lift the Toyota Prius vehicle.

Click here

(b) Fasten the driver seat belt.

(c) Turn the ignition switch to ON (READY).

(d) Ensure that the rear seat belt is fastened, and then unfasten it.

(e) Check that the seat belt warning buzzer (in the combination meter assembly) sounds once when the rear seat belt is fastened and then unfastened, and then the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or higher.

(f) After 18 seconds have passed after the buzzer sounds once, check that the seat belt warning buzzer (in the combination meter assembly) sounds intermittently at 1.2-second intervals for 6 seconds.

(g) After the buzzer has sounded intermittently at 1.2-second intervals for 6 seconds, check that the interval changes and the buzzer sounds intermittently at 0.4-second intervals for 66 seconds.

(h) When 72 seconds have passed after the buzzer started sounding intermittently, check that the seat belt warning buzzer (in the combination meter assembly) stops.

(i) After the seat belt warning buzzer (in the combination meter assembly) stops, check that the buzzer sounds once and then once again sounds intermittently when the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or higher with the rear seat belt unfastened.

(j) Check that the seat belt warning buzzer (in the combination meter assembly) stops when the shift position is changed to R while the seat belt warning buzzer (in the combination meter assembly) is sounding.

Check that the buzzer once again sounds intermittently when the shift position is changed to D again and the Toyota Prius vehicle is driven at approximately 5 km/h (3 mph) or higher with the rear seat belt unfastened.

Customize Parameters

CUSTOMIZE PARAMETERS

CUSTOMIZE SEAT BELT WARNING SYSTEM

HINT:

The following items can be customized.

(a) Customizing with the GTS

(1) Connect the GTS to the DLC3.

(2) Turn the ignition switch to ON.

(3) Turn the GTS on.

(4) Enter the following menus: Customize Setting / Warning.

(5) Select the setting by referring to the table below.

Warning

Tester Display	Description	Default	Setting	ECU
Driver Seatbelt Warning Buzzer Function	Enables sounding of the driver seat belt warning buzzer	ON	$00:OFF,$01:ON	Combination meter assembly
Passenger Seatbelt Warning Buzzer Function	Enables sounding of the front passenger seat belt warning buzzer	ON	$00:OFF,$01:ON	Combination meter assembly
Rear Right Seatbelt Warning Buzzer Function	Enables sounding of the rear RH seat belt warning buzzer	ON	$00:OFF,$01:ON	Combination meter assembly
Rear Left Seatbelt Warning Buzzer Function	Enables sounding of the rear LH seat belt warning buzzer	ON	$00:OFF,$01:ON	Combination meter assembly
Rear Center Seatbelt Warning Buzzer Function	Enables sounding of the rear center seat belt warning buzzer	ON	$00:OFF,$01:ON	Combination meter assembly

HINT:

These settings are only valid when the Toyota Prius vehicle is driven at approximately 20 km/h (12 mph) or more.

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

HINT:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.

Seat Belt Warning System

Symptom	Suspected Area	Link
Driver side seat belt warning light does not operate	Refer to the "Driver side seat belt warning light does not operate''
Front passenger side seat belt warning light does not operate	Refer to the "Front passenger side seat belt warning light does not operate''
Rear seat belt warning light malfunction	Refer to the "Rear Seat Belt Warning Light Malfunction"
Driver and front passenger seat belt warning light does not operate	Combination meter assembly
Seat belt warning buzzer does not operate	Check customized settings using the GTS
	Combination meter assembly

Terminals Of Ecu

TERMINALS OF ECU

CHECK POWER DISTRIBUTION BOX ASSEMBLY AND MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Remove the main body ECU (multiplex network body ECU) from the power distribution box assembly.

Click here

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

Terminal No. (Symbol)	Terminal Description	Condition	Specified Condition
z1-13 (GND1) - Body ground	Ground	Always	Below 1 Ω
z1-14 (GND2) - Body ground	Ground	Always	Below 1 Ω
z1-26 (BECU) - Body ground	Auxiliary battery power supply	Ignition switch off	11 to 14 V
z1-27 (IGR) - Body ground	IG power supply	Ignition switch ON	11 to 14 V
		Ignition switch off	Below 1 V

(c) Reconnect the power distribution box assembly connectors.

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

Terminal No. (Symbol)	Terminal Description	Condition	Specified Condition
R17-1 (RCTY) - Body ground	Rear door courtesy light switch (for RH) input	Rear door RH open → closed	Below 1 V → 11 to 14 V or pulse output (maximum 14 V)
R17-26 (LCTY) - Body ground	Rear door courtesy light switch (for LH) input	Rear door LH open → closed	Below 1 V → 11 to 14 V or pulse output (maximum 14 V)
R17-4 - Body ground	Rear center seat belt buckle switch signal	Rear center seat belt fastened	11 to 14 V
		Rear center seat belt unfastened	Below 1 V
R17-8 - Body ground	Rear RH seat belt buckle switch signal	Rear RH seat belt fastened	11 to 14 V
		Rear RH seat belt unfastened	Below 1 V
R17-19 - Body ground	Rear LH seat belt buckle switch signal	Rear LH seat belt fastened	11 to 14 V
		Rear LH seat belt unfastened	Below 1 V

CHECK AIRBAG ECU ASSEMBLY

Terminal No.	Terminal Symbol	Destination
R1-18	GNDR	Front seat inner belt assembly RH
R1-27	RBE
R1-24	SVC	Occupant classification sensor (Front seat adjuster assembly RH)
R1-31	SGD
R1-32	SIG

CHECK COMBINATION METER ASSEMBLY

(a) Disconnect the K18 combination meter assembly connector.

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

HINT:

Measure the values on the wire harness side with the connector disconnected.

Terminal No. (Symbol)	Terminal Description	Condition	Specified Condition
K18-1 (EP) - Body ground	Ground	Always	Below 1 Ω
K18-2 (ES) - Body ground	Ground	Always	Below 1 Ω
K18-5 (B) - Body ground	Auxiliary battery power supply	Always	11 to 14 V
K18-6 (IG ) - Body ground	Ignition power supply	Ignition switch off	Below 1 V
		Ignition switch ON	11 to 14 V
K18-29 (BKL) - Body ground	Driver side seat belt buckle switch signal	Driver side seat belt fastened	1 MΩ or higher
		Driver side seat belt unfastened	Below 1 Ω

Diagnosis System

DIAGNOSIS SYSTEM

CHECK DLC3

(a) Check the DLC3.

Click here

INSPECT AUXILIARY BATTERY VOLTAGE

(a) Measure the auxiliary battery voltage with the ignition switch off.

Standard Voltage:

11 to 14 V

If the voltage is below 11 V, recharge or replace the auxiliary battery.

Data List / Active Test

DATA LIST / ACTIVE TEST

DATA LIST

NOTICE:

In the following table, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

HINT:

Using the GTS to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

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

Body Electrical > Combination Meter > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Driver Buckle Switch	Driver seat belt buckle switch	Fastened or Not Fastened	Fastened: Driver seat belt buckle switch fastened Not Fastened: Driver seat belt buckle switch unfastened	-
Driver Seatbelt Warning Buzzer Function	Driver seat belt warning buzzer	OFF or ON	Customize setting displayed	-
Passenger Seatbelt Warning Buzzer Function	Front passenger seat belt warning buzzer	OFF or ON	Customize setting displayed	-
Rear Right Seatbelt Warning Buzzer Function	Rear RH seat belt warning buzzer	OFF or ON	Customize setting displayed	-
Rear Left Seatbelt Warning Buzzer Function	Rear LH seat belt warning buzzer	OFF or ON	Customize setting displayed	-
Rear Center Seatbelt Warning Buzzer Function	Rear center seat belt warning buzzer	OFF or ON	Customize setting displayed	-

Body Electrical > Power Distribution Box > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Passenger Seat Buckle Switch Status	Front passenger seat belt buckle switch	Set, Unset or Unknown	Set: Front passenger seat belt buckle switch fastened Unset: Front passenger seat belt buckle switch unfastened Unknown: Data is not determined	Although the item is displayed on the GTS, it is not applicable to this Toyota Prius vehicle.
Passenger Seat Occupant Sensor Status	Front passenger occupant detection sensor	OFF, ON or Unknown	OFF: Front passenger seat not occupied ON: Front passenger seat occupied Unknown: Data is not determined	Although the item is displayed on the GTS, it is not applicable to this Toyota Prius vehicle.
Rear Seat RH Buckle Switch Status	Rear RH seat belt buckle switch	Set, Unset or Unknown	Set: Rear RH seat belt buckle switch fastened Unset: Rear RH seat belt buckle switch unfastened Unknown: Data is not determined	-
Rear Seat Center Buckle Switch Status	Rear center seat belt buckle switch	Set, Unset or Unknown	Set: Rear center seat belt buckle switch fastened Unset: Rear center seat belt buckle switch unfastened Unknown: Data is not determined	-
Rear Seat LH Buckle Switch Status	Rear LH seat belt buckle switch	Set, Unset or Unknown	Set: Rear LH seat belt buckle switch fastened Unset: Rear LH seat belt buckle switch unfastened Unknown: Data is not determined	-

Body Electrical > Main Body > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
RR Door Courtesy Switch Status	Rear door courtesy light switch RH	Close or Open	Close: Rear door RH closed Open: Rear door RH open	-
RL Door Courtesy Switch Status	Rear door courtesy light switch LH	Close or Open	Close: Rear door LH closed Open: Rear door LH open	-

Body Electrical > SRS Airbag > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Driver Seat Buckle Switch Status	Driver seat belt buckle switch	Unknown, Unbuckle, Buckle, Malfunction	Unknown: Data is not determined Unbuckle: Driver seat belt buckle switch unfastened Buckle: Driver seat belt buckle switch fastened Malfunction: Driver seat belt buckle switch is malfunctioning	Although the item is displayed on the GTS, it is not applicable to this Toyota Prius vehicle.
Passenger Seat Buckle Switch Status	Passenger seat belt buckle switch	Unknown, Unbuckle, Buckle, Malfunction	Unknown: Data is not determined Unbuckle: Front passenger seat belt buckle switch unfastened Buckle: Front passenger seat belt buckle switch fastened Malfunction: Front passenger seat belt buckle switch is malfunctioning	-

ACTIVE TEST

HINT:

Using the GTS to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

(a) Perform the Active Test according to the display on the GTS.

Body Electrical > Combination Meter > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Driver Side Seat Belt Warning	Driver seat belt warning light	OFF or ON	-
Rear Seat Belt Warning	Rear seat belt warning light	OFF or ON	-

Driver Side Seat Belt Warning Light does not Operate

DESCRIPTION

The combination meter assembly blinks or turns off the seat belt warning light on the combination meter assembly in accordance with the state of the front seat inner belt assembly of the driver seat.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1.	PERFORM ACTIVE TEST USING GTS

(a) Perform the Active Test according to the display on the GTS.

Body Electrical > Combination Meter > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Driver Side Seat Belt Warning	Front seat belt warning light	ON or OFF	-

OK:

The GTS display changes correctly in response to the warning light condition.

OK

REPLACE COMBINATION METER ASSEMBLY

NG

2.	READ VALUE USING GTS

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

Body Electrical > Combination Meter > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Driver Buckle Switch	Driver side seat belt buckle switch	Fastened or Not Fastened	Fastened: Driver seat belt buckle switch fastened Not Fastened: Driver seat belt buckle switch unfastened	-

Body Electrical > Combination Meter > Data List

Tester Display
Driver Buckle Switch

OK:

The GTS display changes correctly in response to the driver seat belt condition.

OK

REPLACE COMBINATION METER ASSEMBLY

NG

3.	INSPECT FRONT SEAT INNER BELT ASSEMBLY LH

Click here

NG

REPLACE FRONT SEAT INNER BELT ASSEMBLY LH

OK

4.	CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT ASSEMBLY LH - COMBINATION METER ASSEMBLY AND BODY GROUND)

(a) Disconnect the K18 combination meter assembly connector.

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

Standard Resistance:

Click Location & Routing(R64,K18) Click Connector(R64) Click Connector(K18)

Tester Connection	Condition	Specified Condition
R64-3 ( ) - K18-29 (BKL)	Always	Below 1 Ω
R64-3 ( ) or K18-29 (BKL) - Body ground	Always	10 kΩ or higher
R64-2 (E) - Body ground	Always	Below 1 Ω

OK

REPLACE COMBINATION METER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

Front Passenger Side Seat Belt Warning Light does not Operate

DESCRIPTION

When the ignition switch is turned to ON, the airbag ECU assembly receives signals to indicate the state of the front seat inner belt assembly LH and also whether the front passenger seat is occupied. The airbag ECU assembly sends those signals to the combination meter assembly via CAN communication. The seat belt warning light on the combination meter assembly illuminates, blinks or turns off in accordance with these signals.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

The seat belt warning system uses the CAN communication system. First, confirm that there are no malfunctions in the CAN communication system. Refer to How to Proceed with Troubleshooting.

Click here

PROCEDURE

1.	CHECK DTC OUTPUT (AIRBAG SYSTEM AND OCCUPANT CLASSIFICATION SYSTEM)

(a) Clear the DTCs.

Body Electrical > SRS Airbag > Clear DTCs

(b) Check for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTCs are output	B

A

REPLACE COMBINATION METER ASSEMBLY

B

GO TO OCCUPANT CLASSIFICATION SYSTEM

Rear Seat Belt Warning Light Malfunction

DESCRIPTION

The power distribution box assembly sends a signal indicating a rear seat belt status when the ignition switch is ON to the main body ECU (multiplex network body ECU) via CXPI communication.

The main body ECU (multiplex network body ECU) sends a signal indicating the rear door courtesy light switch status when the ignition switch is ON or off and a signal indicating a rear seat belt status when the ignition switch is ON to the combination meter assembly via CAN communication.

Depending on the rear door courtesy light switch signal, shift position and Toyota Prius vehicle speed, the combination meter assembly illuminates or turns off the rear seat belt warning light.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1.	READ VALUE USING GTS

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

Body Electrical > Main Body > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
RR Door Courtesy Switch Status	Rear door courtesy light switch (RH) signal	Close or Open	Close: Rear door RH closed Open: Rear door RH open	-
RL Door Courtesy Switch Status	Rear door courtesy light switch (LH) signal	Close or Open	Close: Rear door LH closed Open: Rear door LH open	-

Body Electrical > Main Body > Data List

Tester Display
RR Door Courtesy Switch Status
RL Door Courtesy Switch Status

OK:

The GTS display changes correctly in response to the rear door courtesy light switch condition.

NG

GO TO LIGHTING SYSTEM (Proceed to Rear Door Courtesy Switch Circuit)

OK

2.	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	Range	Normal Condition	Diagnostic Note
Rear Seat RH Buckle Switch Status	Rear RH seat belt buckle switch	Set, Unset or Unknown	Set: Rear RH seat belt buckle switch fastened Unset: Rear RH seat belt buckle switch unfastened Unknown: Data is not determined	-
Rear Seat Center Buckle Switch Status	Rear center seat belt buckle switch	Set, Unset or Unknown	Set: Rear center seat belt buckle switch fastened Unset: Rear center seat belt buckle switch unfastened Unknown: Data is not determined	-
Rear Seat LH Buckle Switch Status	Rear LH seat belt buckle switch	Set, Unset or Unknown	Set: Rear LH seat belt buckle switch fastened Unset: Rear LH seat belt buckle switch unfastened Unknown: Data is not determined	-

Body Electrical > Power Distribution Box > Data List

Tester Display
Rear Seat RH Buckle Switch Status
Rear Seat Center Buckle Switch Status
Rear Seat LH Buckle Switch Status

OK:

The GTS display changes correctly in response to the rear seat belt buckle switch condition.

Result	Proceed to
OK	A
NG (Unknown displayed)	B
NG (Rear RH seat belt malfunction)	C
NG (Rear center seat belt malfunction)	D
NG (Rear LH seat belt malfunction)	E

A

REPLACE COMBINATION METER ASSEMBLY

B

REPLACE POWER DISTRIBUTION BOX ASSEMBLY

D

GO TO STEP 5

E

GO TO STEP 7

C

3.	INSPECT REAR SEAT INNER BELT ASSEMBLY RH

Click here

NG

REPLACE REAR SEAT INNER BELT ASSEMBLY RH

OK

4.	CHECK HARNESS AND CONNECTOR (REAR SEAT INNER BELT ASSEMBLY RH - POWER DISTRIBUTION BOX ASSEMBLY AND BODY GROUND)

(a) Disconnect the R17 power distribution box assembly connector.

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

Standard Resistance:

Click Location & Routing(R54,R17) Click Connector(R54) Click Connector(R17)

Tester Connection	Condition	Specified Condition
R54-5 (RBR ) - R17-8	Always	Below 1 Ω
R54-5 (RBR ) or R17-8 - Body ground	Always	10 kΩ or higher
R54-4 (RBR-) - Body ground	Always	Below 1 Ω

OK

REPLACE POWER DISTRIBUTION BOX ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	INSPECT REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH

Click here

NG

REPLACE REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH

OK

6.	CHECK HARNESS AND CONNECTOR (REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH - POWER DISTRIBUTION BOX ASSEMBLY AND BODY GROUND)

(a) Disconnect the R17 power distribution box assembly connector.

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

Standard Resistance:

Click Location & Routing(R55,R17) Click Connector(R55) Click Connector(R17)

Tester Connection	Condition	Specified Condition
R55-1 (CBR ) - R17-4	Always	Below 1 Ω
R55-2 (CBR-) - Body ground	Always	Below 1 Ω
R55-1 (CBR ) or R17-4 - Body ground	Always	10 kΩ or higher

OK

REPLACE POWER DISTRIBUTION BOX ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	INSPECT REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH

Click here

NG

REPLACE REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH

OK

8.	CHECK HARNESS AND CONNECTOR (REAR SEAT INNER WITH CENTER BELT ASSEMBLY LH - POWER DISTRIBUTION BOX ASSEMBLY AND BODY GROUND)

(a) Disconnect the R17 power distribution box assembly connector.

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

Standard Resistance:

Click Location & Routing(R53,R17) Click Connector(R53) Click Connector(R17)

Tester Connection	Condition	Specified Condition
R53-5 (LBR ) - R17-19	Always	Below 1 Ω
R53-4 (LBR-) - Body ground	Always	Below 1 Ω
R53-5 (LBR ) or R17-19 - Body ground	Always	10 kΩ or higher

OK

REPLACE POWER DISTRIBUTION BOX ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR