DTC B1FAC

DTC B1FAC : Left rear heater current abnormal low (second row seat)

DTC Description	DTC
B1FAC Left rear heater current abnormal low (second row seat)

DTC (Second Row Seat Heater Control Unit)

NOTE:

If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks (2014 2015 2016) or Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks (2017 2018 2019 2020) .
The seat heater control unit does not turn on the seat heater until the seat core temperature is 85 degrees or less. Make sure the seat core temperature is below 85 degrees before troubleshooting.

Problem verification

-1. Clear the DTCs with the HDS.

- 2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

- 3. Check for DTCs with the HDS.

DTC Description	DTC
B1FAC Left rear heater current abnormal low (second row seat)

Is DTC B1FAC indicated?

YES

Go to step 2.

Intermittent failure, the system is OK at this time. Check for loose or poor connections.

DTC check

-1. Turn the vehicle to the OFF (LOCK) mode.

- 2. Disconnect the following connector.

Left second row seat heater connector B (3P) - Refer to: Seat Heater Replacement(Seat Heaters), or Seat Heater Replacement - Ventilated Seats(Ventilated Seats), or Seat Heater Replacement (2017 2018 2019 2020)

- 3. Connect terminals A and B with a jumper wire.

Terminal A	Left second row seat heater connector B (3P) No. 3 (RED)
Terminal B	Body ground

Courtesy of HONDA, U.S.A., INC.

- 4. Turn the vehicle to the ON mode.

- 5. Clear the DTCs with the HDS.

- 6. Check for DTCs with the HDS.

DTC Description	DTC
B1FAC Left rear heater current abnormal low (second row seat)

Is DTC B1FAC indicated?

YES

Repair an open or high resistance in the wire.

Go to step 3.

Seat heater check

-1. Measure the resistance between test points 1 and 2, refer to the following table.

Test condition	Vehicle OFF (LOCK) modeLeft second row seat heater connector B (3P): disconnected
Test circuit	RR L HEATER, GND
Test point 1	Left second row seat heater connector B (3P) No. 1
Test point 2	Left second row seat heater connector B (3P) No. 3

Courtesy of HONDA, U.S.A., INC.

Is there more than 6.1 Ω ?

YES

Replace the left second row seat-back heater - Refer to: Seat Heater Replacement (2017 2018 2019 2020), or Seat Heater Replacement(Seat Heaters), or Seat Heater Replacement - Ventilated Seats(Ventilated Seats) .

Go to step 4.

Open wire check (HTR CUSH TO BACK line)

-1. Disconnect the following connector.

Left second row seat heater connector A (4P) - Refer to: Seat Heater Replacement (2017 2018 2019 2020), or Seat Heater Replacement(Seat Heaters), or Seat Heater Replacement - Ventilated Seats(Ventilated Seats)

- 2. Connect terminals A and B with a jumper wire.

Terminal A	Left second row seat heater connector A (4P) No. 4 (BLU)
Terminal B	Body ground

Courtesy of HONDA, U.S.A., INC.

- 3. Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) modeLeft second row seat heater connector B (3P): disconnected
Test circuit	HTR CUSH TO BACK
Test point 1	Left second row seat heater connector B (3P) No. 2 (BLU)
Test point 2	Body ground

Courtesy of HONDA, U.S.A., INC.

Is there continuity?

YES

Replace the left second row seat cushion heater - Refer to: Seat Heater Replacement(Seat Heaters), or Seat Heater Replacement - Ventilated Seats(Ventilated Seats), or Seat Heater Replacement (2017 2018 2019 2020) .

Repair an open or high resistance in the wire.