SEAT VENTILATION UNIT INSPECTION

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•  When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunction. If there is a problem, inspect to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

System Diagram

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Symptom Trouble Shooting Index

No.

Troubleshooting item
1
Seat ventilation function is inoperative (See Inspection Procedure (No.1 Seat Ventilation Function Is Inoperative).)
2
Seat ventilation always operations (See Inspection Procedure (No.2 Seat Ventilation Always Operations).)

Inspection Procedure (No.1 Seat Ventilation Function Is Inoperative)

No.1

Seat ventilation function is inoperative
POSSIBLE CAUSE
•  Open circuit in seat ventilation unit power supply circuit:
?  Seat ventilation unit terminal B and battery positive terminal
•  SEAT WARM 20 A fuse malfunction (Blown fuse):
?  Seat ventilation unit terminal B and battery positive terminal
•  Poor connect the connector:
?  Driver-side seat ventilation unit connector and front seat warmer control unit connector
?  Passenger-side seat ventilation Seat ventilation unit connector and front seat warmer control unit connector
•  Open circuit in wiring harness between the following terminal:
?  Driver-side seat ventilation terminal D and front seat warmer control unit terminal E
?  Passenger-side seat ventilation terminal D and front seat warmer control unit terminal E
•  Open circuit or short to ground in wiring harness between the following terminal:
?  Seat ventilation unit terminal C and body ground
Front seat warmer control unit cannot receive operation signal
•  Front seat warmer control unit malfunction
•  Open circuit or short to ground in wiring harness between the following terminal:
?  Front seat warmer control unit terminal F and climate control unit terminal 1I

Diagnostic procedure

STEP

INSPECTION

ACTION
1
PERFORM DTC INSPECTION
•  Verify the instrument cluster DTC inspection.
•  Are DTCs and error codes output?
Yes
Perform the diagnosis according to the inspection procedure for each code.
(See DTC TABLE [INSTRUMENT CLUSTER].)
No
Go to the next step.
2
DETERMINE IF THE MALFUNCTION CAUSE IS THE SEAT VENTILATION SWITCH
•  Select either Low, Mid, or High on the seat ventilation switch.
•  Does the seat ventilation switch LED illuminate?
Yes
Go to the next step.
No
Inspect the climate control unit.
(See FRONT CLIMATE CONTROL UNIT INSPECTION.)
3
DETERMINE MALFUNCTIONING SYSTEM
•  Are the seat ventilations on both sides not operating?
Yes
Go to step 8.
No
Go to the next step.
4
INSPECT THE SEAT VENTILATION UNIT POWER SUPPLY FUSE
•  Inspect the SEAT WARM 20 A fuse.
•  Is the fuse normal?
Yes
Go to the next step.
No
•  If the fuse is deterioration:
?  Replace the malfunctioning fuse.
•  If the fuse is blown
Repair the short to ground in wiring harness between the following terminals:
?  SEAT WARM 20 A fuse and seat ventilation unit terminal D
5*
DETERMINE IF CAUSE OF MALFUNCTION IS CONTROLLER POWER SUPPLY WIRING HARNESS FOR SEAT VENTILATION OR OTHER CAUSE
•  Switch the ignition off (LOCK).
•  Disconnect the seat ventilation unit connector.
•  Measure the voltage at the following terminal (wiring harness-side):
?  Seat ventilation unit terminal D
•  Is the voltage B+?
Yes
Go to the next step.
No
•  Repair or replace the open circuit at the following wiring harness.
?  SEAT WARM 20 A fuse and seat ventilation unit terminal D
6*
VERIFY IF MALFUNCTION CAUSE IS SHORT TO GROUND IN SEAT VENTILATION UNIT
•  Seat ventilation unit connector on the side that is not operating is disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
?  Seat ventilation unit terminal on the side that is not operating C and body ground
•  Is there continuity?
Yes
Go to the next step.
No
•  Inspect the open circuit following.
?  Seat ventilation unit terminal C and body ground
•  Inspect the body ground connector terminals for poor connection.
•  Repair or replace the malfunction.
7*
VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS OF SEAT VENTILATION SWITCH SIGNAL
•  Front seat warmer control unit connector is disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
•  Front seat warmer control unit terminal F and climate control unit terminal 1I
•  Is there continuity?
Yes
Go to the next step.
No
•  Inspect the open circuit following.
?  Front seat warmer control unit terminal F and climate control unit terminal 1I
8*
INSPECT FRONT SEAT WARMER CONTROL UNIT AND FRONT SEAT VENTILATION UNIT CONNECTOR
•  Disconnect the front seat warmer control unit and seat ventilation unit connector on the side not operating.
•  Inspect the front seat warmer control unit and seat ventilation unit connector terminals for poor connection (such as damaged/pulled-out pins, and corrosion).
•  Is there any malfunction?
Yes
Repair or replace the malfunctions.
No
Go to the next step.
9*
VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS OF SEAT VENTILATION UNIT CIRCUIT
•  Switch the ignition off (LOCK).
•  Disconnect the front seat warmer control unit connector.
•  Inspect for continuity between the following terminals (wiring harness-side):
?  Driver-side seat ventilation unit terminal D and front seat warmer control unit terminal E
?  Passenger-side seat ventilation unit terminal D and front seat warmer control unit terminal E
•  Is there continuity?
Yes
Go to the next step.
No
Replace the front seat.
(See FRONT SEAT REMOVAL/INSTALLATION.)
10
DETERMINE IF THE MALFUNCTION CAUSE IS SEAT VENTILATION UNIT
•  Replace the climate control unit.
•  Does the seat ventilation system operate?
Yes
Troubleshooting completed.
No
Replace the front seat.
(See FRONT SEAT REMOVAL/INSTALLATION.)


Inspection Procedure (No.2 Seat Ventilation Always Operations)

No.2

Seat ventilation always operations
POSSIBLE CAUSE
Seat ventilation switch is always ON
•  Seat ventilation switch malfunction
Seat ventilation unit falsely detects seat ventilation switch is ON
•  Front seat warmer control unit malfunction
•  Short circuit in wiring harness between the following terminal:
?  Front seat warmer control unit terminal F and climate control unit terminal 1I

Diagnostic procedure

STEP

INSPECTION

ACTION
1*
DETERMINE IF THE MALFUNCTION CAUSE IS THE SEAT VENTILATION SWITCH
•  Switch the ignition off (LOCK).
?  Disconnect the climate control unit connector.
•  Switch the ignition ON (engine off or on).
•  Is the seat ventilation system operating?
Yes
Go to the next step.
No
Replace the climate control unit.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
2
DETERMINE IF THE MALFUNCTION CAUSE IS THE FRONT SEAT WARMER CONTROL UNIT
•  Disconnect the front seat warmer control unit connector.
•  Measure the voltage between front seat warmer control unit terminal F and body ground.
•  Is the voltage 1.0 or more?
Yes
Repair or replace for a short to ground in the wiring harness.
No
Replace the front seat.
(See FRONT SEAT REMOVAL/INSTALLATION.)