DTC B1C57 (Ventilated Seat Control Unit)

WARNING: This page is about a different car, the 2022 Honda Accord, 2021 Honda Accord, 2020 Honda Accord, 2019 Honda Accord, and 2018 Honda Accord. However, it is still accessible from the selected car via links, so may be relevant.

DTC B1C57 : Passenger's Heater Thermistor Circuit Open

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .

DTC Description	DTC
B1C57 Passenger's heater thermistor circuit open

DTC (Ventilated Seat Control Unit)

Problem verification

-1. Clear the DTCs with the HDS.

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

-3. Turn the front passenger's seat heater switch ON.

-4. Wait for at least 90 seconds.

-5. Check for DTCs with the HDS.

DTC Description	DTC
B1C57 Passenger's heater thermistor circuit open

Is DTC B1C57 indicated?

YES

Go to step 2.

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

Seat heater check 1

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

-2. Disconnect the following connector.

Ventilated seat control unit 24P connector

-3. Measure the resistance between test points 1 and 2, refer to the following table.

Test condition	Vehicle OFF (LOCK) mode Ventilated seat control unit 24P connector: disconnected
Test point 1	Ventilated seat control unit 24P connector No. 13
Test point 2	Ventilated seat control unit 24P connector No. 23

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

Is resistance value within the range?

YES

Replace the ventilated seat control unit .

Go to step 3.

Seat heater check 2

-1. Disconnect the following connector.

Front passenger's seat heater connector A (4P)

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

Test condition	Vehicle OFF (LOCK) mode Ventilated seat control unit 24P connector: disconnected Front passenger's seat heater connector A (4P): disconnected
Test point 1	Front passenger's seat heater connector A (4P) (male terminals) No. 3:
Test point 2	Front passenger's seat heater connector A (4P) (male terminals) No. 4:

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

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

Is resistance value within the range?

YES

Replace the ventilated seat control unit .

Go to step 4.

Open wire check (TH+ AS line)

-1. Connect terminals A and B with a jumper wire.

Terminal A	Front passenger's seat heater connector A (4P) (female terminals) No. 3:
Terminal B	Body ground

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

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

Test condition	Vehicle OFF (LOCK) mode Ventilated seat control unit 24P connector: disconnected Front passenger's seat heater connector A (4P): disconnected Front passenger's seat heater connector A (4P): jumped to body ground
Test point 1	Ventilated seat control unit 24P connector No. 13
Test point 2	Body ground

Is there continuity?

YES

Repair an open or high resistance in the TH- AS wire.

Repair an open or high resistance in the TH+ AS wire.