F-CAN Circuit Troubleshooting (L4: With ACC) - Honda Accord CR/CT 2012-2017

1.

F-CAN circuit resistance check:

F-CAN circuit resistance check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Jump the SCS line with the HDS.

?3.

Disconnect the following connector.

PCM connector A (51P)

?4.

Measure the resistance between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
Test circuit	F-CAN_H, F-CAN_L
Test point 1	PCM connector A (51P) No. 2 (WHT)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there about 47?60 ??


	YES

Go to step 13


	NO

Go to step 2.

2.

Shorted wire check (F-CAN_H line to F-CAN_L line):

Shorted wire check (F-CAN_H line to F-CAN_L line)

?1.

Disconnect the following connectors.

NOTE: Before disconnecting the SRS unit connector, do the 12 volt battery terminal disconnection procedure, and wait for at least 3 minutes.

	Gauge control module connector A (32P)
	VSA modulator-control unit 38P connector
	Steering angle sensor 4P connector
	EPS control unit connector A (11P)
	Keyless access control unit connector C (24P)
	SRS unit connector A (39P)
	Audio-navigation unit connector D (18P) (with navigation)
	ANC/active sound control unit 20P connector
	Multipurpose camera unit 20P connector (with ACC)

?2.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H, F-CAN_L
Test point 1	PCM connector A (51P) No. 2 (WHT)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there continuity?


	YES

Repair a short in the F-CAN_H wire to F-CAN_L wire between PCM terminals A1 and A2.?


	NO

The F-CAN_H and F-CAN_L wires are not shorted. Go to step 3.

3.

Open wire check (F-CAN_H line) 1:

Open wire check (F-CAN_H line) 1

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H
Test point 1	Gauge control module connector A (32P) No. 19 (WHT)
Test point 2	PCM connector A (51P) No. 2 (WHT)

Is there continuity?


	YES

The F-CAN_H wire is not open. Go to step 4.


	NO

Repair an open in the F-CAN_H wire between the PCM (A2) and the gauge control module.?

4.

Open wire check (F-CAN_H line) 2:

Open wire check (F-CAN_H line) 2

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H
Test point 1	VSA modulator-control unit 38P connector No. 38 (WHT)
Test point 2	PCM connector A (51P) No. 2 (WHT)

Is there continuity?


	YES

The F-CAN_H wire is not open. Go to step 5.


	NO

Repair an open in the F-CAN_H wire between the PCM (A2) and the VSA modulator-control unit.?

5.

Open wire check (F-CAN_H line) 3:

Open wire check (F-CAN_H line) 3

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H
Test point 1	EPS control unit connector A (11P) No. 10 (WHT)
Test point 2	PCM connector A (51P) No. 2 (WHT)

Is there continuity?


	YES

The F-CAN_H wire is not open. Go to step 6.


	NO

Repair an open in the F-CAN_H wire between the PCM (A2) and the EPS control unit.?

6.

Open wire check (F-CAN_H line) 5:

Open wire check (F-CAN_H line) 5

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H
Test point 1	Multipurpose camera unit 20P connector No. 2 (WHT)
Test point 2	PCM connector A (51P) No. 2 (WHT)

Is there continuity?


	YES

The F-CAN_H wire is not open. Go to step 7.


	NO

Repair an open in the F-CAN_H wire between the PCM (A2) and the multipurpose camera unit.?

7.

Open wire check (F-CAN_L line) 1:

Open wire check (F-CAN_L line) 1

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_L
Test point 1	Gauge control module connector A (32P) No. 20 (RED)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there continuity?


	YES

The F-CAN_L wire is not open. Go to step 8.


	NO

Repair an open in the F-CAN_L wire between the PCM (A1) and the gauge control module.?

8.

Open wire check (F-CAN_L line) 2:

Open wire check (F-CAN_L line) 2

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_L
Test point 1	VSA modulator-control unit 38P connector No. 26 (RED)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there continuity?


	YES

The F-CAN_L wire is not open. Go to step 9.


	NO

Repair an open in the F-CAN_L wire between the PCM (A1) and the VSA modulator-control unit.?

9.

Open wire check (F-CAN_L line) 3:

Open wire check (F-CAN_L line) 3

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_L
Test point 1	EPS control unit connector A (11P) No. 11 (RED)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there continuity?


	YES

The F-CAN_L wire is not open. Go to step 10.


	NO

Repair an open in the F-CAN_L wire between the PCM (A1) and the EPS control unit.?

10.

Open wire check (F-CAN_L line) 5:

Open wire check (F-CAN_L line) 5

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_L
Test point 1	Multipurpose camera unit 20P connector No. 13 (RED)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there continuity?


	YES

The F-CAN_L wire is not open. Go to step 11.


	NO

Repair an open in the F-CAN_L wire between the PCM (A1) and the multipurpose camera unit.?

11.

VSA modulator-control unit internal resistance check:

VSA modulator-control unit internal resistance check

?1.	Reconnect VSA modulator-control unit 38P connector.

?2.

Measure the resistance between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H, F-CAN_L
Test point 1	PCM connector A (51P) No. 2 (WHT)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there about 108?132 ??


	YES

The VSA modulator-control unit is OK. Disconnect the VSA modulator-control unit 38P connector, then go to step 12.


	NO

Replace the VSA modulator-control unit.?

12.

SRS unit internal resistance check:

SRS unit internal resistance check

?1.	Reconnect SRS unit connector A (39P).

?2.

Measure the resistance between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H, F-CAN_L
Test point 1	PCM connector A (51P) No. 2 (WHT)
Test point 2	PCM connector A (51P) No. 1 (RED)

Is there about 108?132 ??


	YES

The SRS unit is OK. Disconnect SRS unit connector A (39P), then go to step 13.


	NO

Replace the SRS unit.?

13.

Shorted wire check (F-CAN_H line):

Shorted wire check (F-CAN_H line)

?1.

Disconnect the following connectors.

	Gauge control module connector A (32P)
	VSA modulator-control unit 38P connector
	Steering angle sensor 4P connector
	EPS control unit connector A (11P)
	Keyless access control unit connector C (24P)
	SRS unit connector A (39P)
	Audio-navigation unit connector D (18P) (with navigation)
	ANC/active sound control unit 20P connector
	Multipurpose camera unit 20P connector (with ACC)

?2.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_H
Test point 1	PCM connector A (51P) No. 2 (WHT)
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the F-CAN_H wire between the PCM (A2) and the gauge control module, the VSA modulator-control unit, the steering angle sensor, the EPS control unit, the keyless access control unit, the SRS unit, the ANC/active sound control unit, the audio-navigation unit, the multipurpose camera unit, or the DLC.?


	NO

The F-CAN_H wire is OK. Go to step 14.

14.

Shorted wire check (F-CAN_L line):

Shorted wire check (F-CAN_L line)

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PCM connector A (51P): disconnected
	Gauge control module connector A (32P): disconnected
	VSA modulator-control unit 38P connector: disconnected
	Steering angle sensor 4P connector: disconnected
	EPS control unit connector A (11P): disconnected
	Keyless access control unit connector C (24P): disconnected
	SRS unit connector A (39P): disconnected
	Audio-navigation unit connector D (18P): disconnected
	ANC/active sound control unit 20P connector: disconnected
	Multipurpose camera unit 20P connector: disconnected
Test circuit	F-CAN_L
Test point 1	PCM connector A (51P) No. 1 (RED)
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the F-CAN_L wire between the PCM (A1) and the gauge control module, the VSA modulator-control unit, the steering angle sensor, the EPS control unit, the keyless access control unit, the SRS unit, the ANC/active sound control unit, the audio-navigation unit, the multipurpose camera unit, or the DLC.?


	NO

The F-CAN_L wire is OK. Go to step 15.

15.

Gauge control module check:

Gauge control module check

?1.	Reconnect all connectors.

?2.	Connect the HDS to the DLC.

?3.

Disconnect the following connector.

Gauge control module connector A (32P)

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the gauge control module.?


	NO

Go to step 16.

16.

VSA modulator-control unit check:

VSA modulator-control unit check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect the gauge control module connector A (32P).

?3.

Disconnect the following connector.

VSA modulator-control unit 38P connector

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the VSA modulator-control unit.?


	NO

Go to step 17.

17.

Steering angle sensor check:

Steering angle sensor check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect the VSA modulator-control unit 38P connector.

?3.

Disconnect the following connector.

Steering angle sensor 4P connector

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the steering angle sensor.?


	NO (with navigation)

Go to step 18.


	NO (without navigation)

Go to step 19.

18.

Navigation unit check:

Navigation unit check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect the steering angle sensor 4P connector.

?3.

Disconnect the following connector.

Audio-navigation unit connector D (18P)

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the audio-navigation unit.?


	NO

Go to step 19.

19.

EPS control unit check:

EPS control unit check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect the steering angle sensor 4P connector (without navigation) or the audio-navigation unit connector D (18P) (with navigation).

?3.

Disconnect the following connector.

EPS control unit connector A (11P)

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the EPS control unit.?


	NO

Go to step 20.

20.

ANC/active sound control unit check:

ANC/active sound control unit check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect the EPS control unit connector A (11P).

?3.

Disconnect the following connector.

ANC/active sound control unit 20P connector

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the ANC/active sound control unit.?


	NO

Go to step 21.


	NO

Go to step 22.

21.

Multipurpose camera unit check:

Multipurpose camera unit check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect the ANC/active sound control unit 20P connector.

?3.

Disconnect the following connector.

Multipurpose camera unit 20P connector

?4.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the multipurpose camera unit.?


	NO

Go to step 22.

22.

SRS unit check:

SRS unit check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.	Reconnect the ANC/active sound control unit 20P connector (without ACC) or the multipurpose camera unit 20P connector (with ACC).

?3.	Do the battery terminal disconnection procedure, and wait for at least 3 minutes.

?4.

Disconnect the following connector.

SRS unit connector A (39P)

?5.	Do the battery terminal reconnection procedure.

?6.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and read the HDS.

Does the HDS identify the vehicle?


	YES

Replace the SRS unit.?


	NO (Without keyless access system)

Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM.?


	NO (With keyless access system)

	Substitute a known-good keyless access control unit, then recheck. If the HDS identifies the vehicle and the keyless access control unit was substituted, replace the original keyless access control unit.?
	Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM.?