Seat Heater for Front Left Seat does not Operate [10/2023 - ]: Procedure

1. Using the Techstream, perform the Active Test.

   Body Electrical > Air Conditioner > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Front Left Seat Heater	Front seat LH side seat heater operation	OFF/ON	-

   Body Electrical > Air Conditioner > Active Test 

   Tester Display
   Front Left Seat Heater

   OK

   The seat heater operates normally.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  6

Result: 

OK 

See step  2

1. Check the vehicle type.

   Result

   Result	Proceed to
   w/ Audio	A
   w/o Audio	B

Result: 

B 

See step  4

Result: 

A 

See step  3

1. Check that the front left seat heater operates normally by operating the multi-display assembly or the refrating seat switch.

   Refer to OPERATION CHECK [10/2022 - ]

   Result

   Result	Proceed to
   Multi-display assembly and refreshing seat switch operation does not operate.	A
   Multi-display assembly operation does not operate.	B
   Refreshing seat switch operation does not operate.	C

Result: 

A 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2017 - ] 

Result: 

B 

GO TO AUDIO AND VISUAL SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2023 - ] 

Result: 

C 

REPLACE REFRESHING SEAT SWITCH. Refer to  REMOVAL [10/2022 - ] 

1. Temporarily replace the refreshing seat switch with a new or known good one.

   Refer to REMOVAL [10/2022 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Operate the refreshing seat switch and check the front right seat heater operates normally.

   Refer to OPERATION CHECK [10/2022 - ]

   OK

   The seat heater operates normally.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (REFRESHING SEAT SWITCH WAS DEFECTIVE) 

Result: 

NG 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2017 - ] 

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [10/2017 - ]

   Body Electrical > Air Conditioner > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  7

1. Check for DTCs.

   Refer to DTC CHECK / CLEAR [10/2017 - ]

   Body Electrical > Air Conditioner > Trouble Codes 

   OK

   DTC B14C1 is not output.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [10/2017 - ] 

Result: 

OK 

See step  8

1. Disconnect the Q31 seat heater control sub-assembly LH connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   Q31-3 (IG) - Body ground	Power switch on (IG)	11 to 14 V
   	Power switch off	Below 1 V
   Q31-1 (+B1) - Body ground	Power switch off	11 to 14 V
   Q31-8 (+B2) - Body ground	Power switch off	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  9

1. Remove the separate type front seat cushion cover LH.

   Refer to REMOVAL [10/2023 - ]

2. Inspect the separate type front seat cushion cover LH.

   Refer to INSPECTION [10/2017 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE SEPARATE TYPE FRONT SEAT CUSHION COVER LH. Refer to  REMOVAL [10/2023 - ] 

Result: 

OK 

See step  10

1. Remove the separate type front seatback cover LH.

   Refer to REMOVAL [10/2023 - ]

2. Inspect the separate type front seatback cover LH.

   Refer to INSPECTION [10/2017 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE SEPARATE TYPE FRONT SEATBACK COVER LH. Refer to  REMOVAL [10/2023 - ] 

Result: 

OK 

See step  11

1. Disconnect the Q36 separate type front seat cushion cover LH connector.
2. Disconnect the Q31 seat heater control sub-assembly LH connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q36-6 - Q31-10 (E)	Always	Below 1 Ω
   Q36-6 or Q31-10 (E) - Other terminals and body ground	Always	10 kΩ or higher
   Q36-1 - Q31-7 (Heater Output 1)	Always	Below 1 Ω
   Q36-1 or Q31-7 (Heater Output 1) - Other terminals and body ground	Always	10 kΩ or higher
   Q36-3 - Q31-12 (Heater Output 2)	Always	Below 1 Ω
   Q36-3 or Q31-12 (Heater Output 2) - Other terminals and body ground	Always	10 kΩ or higher
   Q36-2 - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  12

1. Disconnect the Q36 separate type front seat cushion cover LH connector.
2. Disconnect the G63 and G64 air conditioning amplifier assembly connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q36-4 - G63-17 (TSL)	Always	Below 1 Ω
   Q36-4 or G63-17 (TSL) - Other terminals and body ground	Always	10 kΩ or higher
   Q36-5 - G64-3 (SG-4)	Always	Below 1 Ω
   Q36-5 or G64-3 (SG-4) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  13

1. Disconnect the Q31 seat heater control sub-assembly LH connector.
2. Disconnect the G63 air conditioning amplifier assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q31-4 (PWM) - G63-15 (SHD+)	Always	Below 1 Ω
   Q31-4 (PWM) or G63-15 (SHD+) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  14

1. Temporarily replace the seat heater control sub-assembly LH with a new or known good one.

   Refer to REMOVAL [10/2023 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  15

1. Check the seat heater.

   Refer to OPERATION CHECK [10/2022 - ]

   OK

   The seat heater operates normally.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (SEAT HEATER CONTROL SUB-ASSEMBLY LH WAS DEFECTIVE) 

Result: 

NG 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2017 - ]