Seat Heater for Front Left Seat does not Operate [02/2017 - 05/2018]: Procedure

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [02/2017 - ]

   Body Electrical > Air Conditioner > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  2

1. Check for DTCs.

   Refer to DTC CHECK / CLEAR [02/2017 - ]

   Body Electrical > Air Conditioner > Trouble Codes 

   OK

   DTC B14B5 is not output.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [02/2017 - 05/2018] 

Result: 

OK 

See step  3

1. Disconnect the seat heater control sub-assembly LH connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Seat Heater Control Sub-assembly LH)

2. Measure the voltage according to the value(s) in the chart below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   Z2-1 (+B1) - Body ground	Ignition switch ON	11 to 14 V
   	Ignition switch off	Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Disconnect the Z2 seat heater control sub-assembly LH connector.
2. Disconnect the Z1 front seat cushion heater assembly LH connector.
3. Measure the resistance according to the value(s) in the chart below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Z2-7 (HTR1) - Z1-1	Always	Below 1 Ω
   Z2-9 (THR+) - Z1-4	Always	Below 1 Ω
   Z2-5 (THR-) - Z1-5	Always	Below 1 Ω
   Z2-10 (E) - Z1-6	Always	Below 1 Ω
   Z1-2 - Body ground	Always	Below 1 Ω
   Z2-7 (HTR1) or Z1-1 - Body ground	Always	10 kΩ or higher
   Z2-9 (THR+) or Z1-4 - Body ground	Always	10 kΩ or higher
   Z2-5 (THR-) or Z1-5 - Body ground	Always	10 kΩ or higher
   Z2-10 (E) or Z1-6 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Remove the front seat cushion heater assembly LH.

   Refer to REMOVAL [02/2017 - 09/2019]

2. Inspect the front seat cushion heater assembly LH.

   Refer to INSPECTION [02/2017 - 05/2018]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE FRONT SEAT CUSHION HEATER ASSEMBLY LH. Refer to  REMOVAL [02/2017 - 09/2019] 

Result: 

OK 

See step  6

1. Remove the front seatback heater assembly LH.

   Refer to REMOVAL [02/2017 - 10/2017] , or refer to REMOVAL [10/2017 - 09/2019]

2. Inspect the front seatback heater assembly LH.

   Refer to INSPECTION [02/2017 - 05/2018]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE FRONT SEATBACK HEATER ASSEMBLY LH. Refer to  REMOVAL [02/2017 - 10/2017]  , or refer to  REMOVAL [10/2017 - 09/2019] 

Result: 

OK 

See step  7

1. Disconnect the F61 seat heater switch (air conditioning control assembly) connector.
2. Disconnect the Z2 seat heater control sub-assembly LH connector.
3. Measure the resistance according to the value(s) in the chart below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F61-12 (SW) - Z2-2 (SWR)	Always	Below 1 Ω
   F61-6 (RV) - Z2-3 (VOL)	Always	Below 1 Ω
   F61-12 (SW) or Z2-2 (SWR) - Body ground	Always	10 kΩ or higher
   F61-6 (RV) or Z2-3 (VOL) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  8

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

   Refer to REMOVAL [02/2017 - 09/2019]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  9

1. Check that the seat heater system is operated normally.

   OK

   The seat heater system is operated normally.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (SEAT HEATER CONTROL SUB-ASSEMBLY WAS DEFECTIVE) 

Result: 

NG 

See step  10

1. Temporarily replace the seat heater switch (air conditioning control assembly) with a new or known good one.

   Refer to REMOVAL [02/2017 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  11

1. Check that the seat heater system is operated normally.

   OK

   The seat heater system is operated normally.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (SEAT HEATER SWITCH (AIR CONDITIONING CONTROL ASSEMBLY) WAS DEFECTIVE) 

Result: 

NG 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [02/2017 - 05/2018]