Electric Brake Booster System Symptom Troubleshooting - Brake system indicator (red) and brake system indicator (amber) do not go off(With ACC)

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.

Brake system indicator (red) and brake system indicator (amber) do not go off

DTC check (Electric brake booster)

-1. Turn the vehicle to the ON mode.

-2. Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame

Is DTC indicated?

YES

Go to indicated DTC's troubleshooting.

Go to step 2.

CAN gateway system DTC check

-1. Check for CAN gateway system DTCs with the HDS.

DTC Description	DTC

DTC (CAN gateway)

Is DTC indicated?

YES

Go to indicated DTC's troubleshooting .

Go to step 3.

Gauge control module operation check
-1. Do the gauge control module self-diagnostic function .

Is the gauge control module OK?

YES

Go to step 4.

NO

Replace the gauge control module .
Fuse check 1
-1. Turn the vehicle to the OFF (LOCK) mode with driver's door open.

-2. Wait for 3 minutes.

NOTE: Do not close the driver's door.

-3. Check the following fuse.

Fuse No. A2-4

Is the fuse OK?

YES

The fuse is OK. Reinstall the fuse, then go to step 5.

NO

Replace the fuse. If the fuse blows again, repair a short to body ground in the No. A2-4 fuse circuit.
Fuse check 2
-1. Check the following fuse.

Fuse No. B35

Is the fuse OK?

YES

The fuse is OK. Reinstall the fuse, then go to step 6.

NO

Replace the fuse. Turn the vehicle to the ON mode, then to the OFF (LOCK) mode. If the fuse blows again, repair a short to body ground in the No. B35 fuse circuit.

Open wire check (IG1 OPTION4 line)

-1. Disconnect the following connector.

Electric brake booster 26P connector

-2. Turn the vehicle to the ON mode.

-3. Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Electric brake booster 26P connector: disconnected
Test point 1	Electric brake booster 26P connector No. 24
Test point 2	Body ground

Is there battery voltage?

YES

The IG1 OPTION4 wire is OK. Go to step 7.

Repair an open in the wire between the No. B35 fuse and the electric brake booster.

Open wire check (+B BOOSTER MTR line)

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

-2. Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Electric brake booster 26P connector: disconnected
Test point 1	Electric brake booster 26P connector No. 2
Test point 2	Body ground

Is there battery voltage?

YES

The +B BOOSTER MTR wire is OK. Go to step 8.

Repair an open in the wire between the No. A2-4 fuse and the electric brake booster.

Open wire check (GND line)

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

Test condition	Vehicle OFF (LOCK) mode
	Electric brake booster 26P connector: disconnected
Test point 1	Electric brake booster 26P connector No. 1
Test point 2	Body ground

Is there continuity?

YES

The GND wire is OK. Go to step 9.

Repair an open in the wire between the electric brake booster and body ground (G303).

F-CAN circuit communication check
-1. Reconnect the following connector.

Electric brake booster 26P connector

-2. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

F-CAN Bus Connected Unit Check

Which result is indicated?

Electric brake booster (Bus A) is Not Available

Go to step 10.

Electric brake booster (Bus B) is Not Available

Go to step 11.

Gauge control module (Bus C) is Not Available

Go to step 12.

Electric brake booster and gauge control module are Available

Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting .

Open wire check (F-CAN A_H, F-CAN A_L lines)

-1. Turn the vehicle to the OFF (LOCK) mode with driver's door open.

-2. Wait for 3 minutes.

NOTE: Do not close the driver's door.

-3. Disconnect the following connectors.

Electric brake booster 26P connector

CAN gateway 16P connector

-4. Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Electric brake booster 26P connector: disconnected
	CAN gateway 16P connector: disconnected
Test point 1	Electric brake booster 26P connector No. 26
Test point 2	CAN gateway 16P connector (female terminals) No. 3:

Test point 1	Electric brake booster 26P connector No. 18
Test point 2	CAN gateway 16P connector (female terminals) No. 11:

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

Is there continuity?

YES

The F-CAN A_H and F-CAN A_L wires are OK. Check for loose terminals and poor connections in the electric brake booster 26P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the electric brake booster .

Repair an open in the wire between the electric brake booster and the CAN gateway.

Open wire check (F-CAN B_H, F-CAN B_L lines)

-1. Turn the vehicle to the OFF (LOCK) mode with driver's door open.

-2. Wait for 3 minutes.

NOTE: Do not close the driver's door.

-3. Disconnect the following connectors.

Electric brake booster 26P connector

CAN gateway 16P connector

-4. Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Electric brake booster 26P connector: disconnected
	CAN gateway 16P connector: disconnected
Test point 1	Electric brake booster 26P connector No. 19
Test point 2	CAN gateway 16P connector (female terminals) No. 6:

Test point 1	Electric brake booster 26P connector No. 12
Test point 2	CAN gateway 16P connector (female terminals) No. 14:

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

Is there continuity?

YES

The F-CAN B_H and F-CAN B_L wires are OK. Check for loose terminals and poor connections in the electric brake booster 26P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the electric brake booster .

Repair an open in the wire between the electric brake booster and the CAN gateway.

Open wire check (F-CAN C_H, F-CAN C_L lines)

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

-2. Disconnect the following connectors.

Gauge control module connector A (32P)

CAN gateway 16P connector

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

Test condition	Vehicle OFF (LOCK) mode
	Gauge control module connector A (32P): disconnected
	CAN gateway 16P connector: disconnected
Test point 1	Gauge control module connector A (32P) No. 20
Test point 2	CAN gateway 16P connector (female terminals) No. 5:

Test point 1	Gauge control module connector A (32P) No. 21
Test point 2	CAN gateway 16P connector (female terminals) No. 13:

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

Is there continuity?

YES

The F-CAN C_H and F-CAN C_L wires are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good gauge control module , then recheck. If the symptom/indication goes away with a known-good gauge control module, replace the original gauge control module .

Repair an open in the wire between the gauge control module and the CAN gateway.