Toyota Prius: Climate Control Seat System

• Precaution
• Parts Location
• System Diagram
• How To Proceed With Troubleshooting
• Operation Check
• Customize Parameters
• Problem Symptoms Table
• Terminals Of Ecu
• Data List / Active Test
• Climate Control System does not Operate on Driver Side

Precaution

PRECAUTION

PRECAUTIONS 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	AIR CONDITIONING AMPLIFIER ASSEMBLY	*2	AIR CONDITIONING CONTROL ASSEMBLY
*3	DLC3	*4	POWER DISTRIBUTION BOX ASSEMBLY - S/HTR F/L FUSE - S/HTR F/R FUSE

ILLUSTRATION

*1	SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH	*2	SEATBACK CLIMATE CONTROL BLOWER LH
*3	SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY RH	*4	SEATBACK CLIMATE CONTROL BLOWER RH (LUMBAR SUPPORT ADJUSTER ASSEMBLY RH)

System Diagram

SYSTEM DIAGRAM

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.	INSPECT 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 FOR DTC*

(a) Clear the DTCs.

Body Electrical > Air Conditioner > Clear DTCs

(b) Check for air conditioning system DTCs.

Body Electrical > Air Conditioner > Trouble Codes

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

B

GO TO AIR CONDITIONING SYSTEM for HEV Model: Click here for PHEV Model: Click here

A

6.	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 8

A

7.	OVERALL ANALYSIS AND TROUBLESHOOTING*

(a) Operation Check

Click here

(b) Data List / Active Test

Click here

(c) Terminals of ECU

Click here

(d) Inspection

NEXT

8.	REPAIR OR REPLACE

NEXT

9.	CONFIRMATION TEST

NEXT

END

Operation Check

OPERATION CHECK

CHECK CLIMATE CONTROL SEAT SYSTEM

(a) Turn the ignition switch to ON.

(b) Operate the climate control switch to switch the seat blower operation in order from HI → MID → LO → OFF and check that the blower level indicator illuminates.

(c) Check that the seat blower volume changes according to the operation of the climate control switch as follows: HI → MID → LO.

Customize Parameters

CUSTOMIZE PARAMETERS

CUSTOMIZE CLIMATE CONTROL SEAT SYSTEM

(a) Customizing with the GTS

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

Air Conditioner

Tester Display	Description	Default	Setting	ECU
Seat Airflow Mode Setting	Function to decrease the airflow volume of the seat blower in each mode	Standard	$00:Standard,$01:Silent (Wind Amount Hi),$02:Silent (Wind Amount Low)	Air conditioning amplifier assembly

Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

NOTICE:

If the climate control seat system is operated when the auxiliary battery voltage is low, due to the electrical load limit control that gives voltage supply priority to the power steering system, the climate control seat system may not operate. In this case, check the Toyota Prius vehicle control history (RoB) of the power steering system and check that "Battery Voltage Drop: X208F" is not stored before proceeding with troubleshooting.

Click here

Climate Control Seat System

Symptom	Suspected Area	Link
Seat blower volume is low (for Driver Seat)	Seat cushion climate control blower assembly LH
	Seatback climate control blower LH
Seat blower volume is low (for Front Passenger Seat)	Seat cushion climate control blower assembly RH
	Seatback climate control blower RH (lumbar support adjuster assembly RH)
Seat blower volume does not change (for Driver Seat)	Air conditioning control assembly
	Seat cushion climate control blower assembly LH
	Seatback climate control blower LH
	Air conditioning amplifier assembly
Seat blower volume does not change (for Front Passenger Seat)	Air conditioning control assembly
	Seat cushion climate control blower assembly RH
	Seatback climate control blower RH (lumbar support adjuster assembly RH)
	Air conditioning amplifier assembly
Both driver side seat blower and front passenger side seat blower do not operate	Air conditioning control assembly
	Air conditioning amplifier assembly
	Power distribution box assembly
	Wire harness or connector	-
Climate control seat system does not operate (for Driver Seat)	Refer to the "Climate Control Seat System does not Operate on Driver Side".
Climate control seat system does not operate (for Front Passenger Seat)	Refer to the "Climate Control Seat System does not Operate on Passenger Side".

Terminals Of Ecu

TERMINALS OF ECU

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

(a) Disconnect the K74 air conditioning amplifier assembly connector.

(b) Measure the voltage and resistance 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
K74-6 (IG ) - K74-17 (GND)	IG power supply	Ignition switch off	Below 1 V
K74-6 (IG ) - K74-17 (GND)	IG power supply	Ignition switch ON	11 to 14 V
K74-17 (GND) - Body ground	Ground	Always	Below 1 Ω

(c) Reconnect the K74 air conditioning amplifier assembly connector.

(d) Check for pulses according to the value(s) in the table below.

Terminal No. (Symbol)	Terminal Description	Condition	Specified Condition
K74-13 (ROUT) - Body ground	RH side climate control blower control signal	Ignition switch ON Climate control switch RH on	Pulse generation (See waveform)
K74-14 (LOUT) - Body ground	LH side climate control blower control signal	Ignition switch ON Climate control switch LH on	Pulse generation (See waveform)

(1) Waveform (Reference):

Measurement Condition

Item	Content
Tester Connection	K74-13 (ROUT) - Body ground K74-14 (LOUT) - Body ground
Tool Setting	1 V/DIV., 1 ms/DIV.
Toyota Prius Vehicle Condition	Ignition switch ON Climate control switch RH on Climate control switch LH on

CHECK AIR CONDITIONING CONTROL ASSEMBLY

Click here

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 > Air Conditioner > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
Seat Airflow Mode Setting	Setting status of seat airflow mode	Standard, Silent (Wind Amount Hi) or Silent (Wind Amount Low)	Customize setting displayed	-
Front Right Seat Blower	RH side front seat blower condition	OFF or ON	OFF: RH side front seat blower does not operate ON: RH side front seat blower operate	-
Front Left Seat Blower	LH side front seat blower condition	OFF or ON	OFF: LH side front seat blower does not operate ON: LH side front seat blower operate	-

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.

ACTIVE TEST

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

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Front Right Seat Blower	Front RH seat blower operation	OFF or ON	-
Front Left Seat Blower	Front LH seat blower operation	OFF or ON	-

Climate Control System does not Operate on Driver Side

DESCRIPTION

The air conditioning amplifier assembly receives ventilation volume switch signals when the ignition switch is ON, and then transmits airflow amount signals to each seat climate blower.

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 > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Front Left Seat Blower	Front LH side seat blower operation	OFF or ON	-

Body Electrical > Air Conditioner > Active Test

Tester Display
Front Left Seat Blower

Result	Proceed to
Both seat cushion seat blower and seatback seat blower operate	A
Only seat cushion seat blower does not operate	B
Only seatback seat blower does not operate	C
Both seat cushion seat blower and seatback seat blower do not operate	D

A

GO TO AIR CONDITIONING SYSTEM for HEV Model: Click here for PHEV Model: Click here

B

REPLACE SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH

D

GO TO STEP 5

C

2.	CHECK HARNESS AND CONNECTOR (SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH - SEATBACK CLIMATE CONTROL BLOWER LH)

(a) Disconnect the b9 seat cushion climate control blower assembly LH connector.

(b) Disconnect the d1 seatback climate control blower LH connector.

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

Standard Resistance:

Click Location & Routing(b9,d1) Click Connector(b9) Click Connector(d1)

Tester Connection	Condition	Specified Condition
b9-2 (CTB) - d1-1 (IG)	Always	Below 1 Ω
b9-2 (CTB) or d1-1 (IG) - Body ground	Always	10 kΩ or higher
b9-5 (BBS) -d1-4 (BFB )	Always	Below 1 Ω
b9-5 (BBS) or d1-4 (BFB ) - Body ground	Always	10 kΩ or higher
b9-7 (BFB-) - d1-7 (GND)	Always	Below 1 Ω
b9-7 (BFB-) or d1-7 (GND) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.	REPLACE SEATBACK CLIMATE CONTROL BLOWER LH

(a) Replace the seatback climate control blower LH with a new or known good one.

Click here

NEXT

4.	CHECK CLIMATE CONTROL SEAT OPERATION

(a) Check the climate control seat operation.

Click here

OK:

The climate control seat operates normally.

OK

END (SEATBACK CLIMATE CONTROL BLOWER LH WAS DEFECTIVE)

NG

REPLACE SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH

5.	CHECK HARNESS AND CONNECTOR (SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH - POWER SUPPLY)

(a) Disconnect the b9 seat cushion climate control blower assembly LH connector.

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

Standard Voltage:

Click Location & Routing(b9) Click Connector(b9)

Tester Connection	Switch Condition	Specified Condition
b9-1 (IG) - Body ground	Ignition switch ON	11 to 14 V
b9-1 (IG) - Body ground	Ignition switch off	Below 1 V

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

Standard Resistance:

Click Location & Routing(b9) Click Connector(b9)

Tester Connection	Condition	Specified Condition
b9-8 (GND) - Body ground	Always	Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.	CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH)

(a) Disconnect the K74 air conditioning amplifier assembly connector.

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

Standard Resistance:

Click Location & Routing(K74,b9) Click Connector(K74) Click Connector(b9)

Tester Connection	Condition	Specified Condition
K74-14 (LOUT) - b9-4 (SIGN)	Always	Below 1 Ω
K74-14 (LOUT) or b9-4 (SIGN) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.	CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

*a	Component with harness connected (Air Conditioning Amplifier Assembly)

(a) Connect the K74 air conditioning amplifier assembly connector.

(b) Connect the b9 seat cushion climate control blower assembly LH connector.

(c) Check for pulses according to the value(s) in the table below.

Measurement Condition

Item	Content
Tester Connection	K74-14 (LOUT) - Body ground
Tool Setting	1 V/DIV., 1 ms/DIV.
Toyota Prius Vehicle Condition	Ignition switch ON Climate control switch LH on

OK:

Waveform is similar to that shown in the illustration.

OK

REPLACE SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH

NG

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY