DTC U0104: F-CAN Malfunction (PCM-Driving Support System Control Unit); DTC U0122: F-CAN Malfunction (PCM-VSA Modulator-Control Unit); DTC U0126: F-CAN Malfunction (PCM-Steering Angle Sensor); DTC U0131: F-CAN Malfunction (PCM-EPS Control Unit); DTC U0155: F-CAN Malfunction (PCM-Gauge Control Module); DTC U129D: F-CAN Malfunction (PCM-Precision All Wheel Steer Control Unit); DTC U129E: F-CAN Malfunction (PCM-Power Control Unit (PCU)) (PGM-FI System (L4)) (2018-19)

NOTE:

Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems (L4) .
According to the detected DTC (s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the PCM.

DTC Description	Confirmed DTC	Pending DTC
U0104 F-CAN Malfunction (PCM-Driving Support System Control Unit)
U0122 F-CAN Malfunction (PCM-VSA Modulator-Control Unit)
U0126 F-CAN Malfunction (PCM- Steering Angle Sensor)
U0131 F-CAN Malfunction (PCM-EPS Control Unit)
U0155 F-CAN Malfunction (PCM-Gauge Control Module)
U129D F-CAN Malfunction (PCM-Precision All Wheel Steer Control Unit)
U129E F-CAN Malfunction (PCM-Power Control Unit (PCU))

DTC (PGM-FI)

CAN gateway system DTC check

-1. Turn the vehicle to the ON mode.

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

DTC Description	DTC

Are any DTCs indicated?

YES

Go to the troubleshooting for CAN gateway system DTC (s) - Refer to: Communication Systems DTC Troubleshooting Index (2018-19) .

Go to step 2.

F-CAN circuit communication check (Receiving control unit)
-1. 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?

Bus A is Not Available

Go to step 3.

Bus A is Available

Go to step 4.

Open wire check (F-CAN_H line, F-CAN_L line)

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

- 2. Jump the SCS line with the HDS, and wait more than 1 minute.

- 3. Disconnect the following connectors.

CAN gateway 16P connector

PCM connector A (51P)

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

Test condition	Vehicle OFF (LOCK) mode
	CAN gateway 16P connector: disconnected
	PCM connector A (51P): disconnected
Test point 1	CAN gateway 16P connector (female terminals) No. 3:
Test point 2	PCM connector A (51P) No. 2 - Refer to: PCM Connector for Inputs and Outputs (L4) (2018-19) .

Test point 1	CAN gateway 16P connector (female terminals) No. 11:
Test point 2	PCM connector A (51P) No. 3 - Refer to: PCM Connector for Inputs and Outputs (L4) (2018-19) .

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

Is there continuity?

YES

The F-CAN_H wire and the F-CAN_L wire are OK. Check for poor connections or loose terminals at the CAN gateway and the PCM. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM - Refer to: PCM Removal and Installation (Without SH-AWD) .

Repair an open in the F-CAN_H wire or the F-CAN_L wire between the PCM (A2, A3) and the CAN gateway.

F-CAN circuit communication check (Transmitting control unit)

-1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

- 2. According to the detected DTC on the following table, make sure that the transmitting control unit detects the CAN gateway Bus channel (s) normally.

DTC	Transmitting control unit	Detected CAN gateway Bus channel (s) at normal
U0104	Multipurpose camera unit	A
U0122	VSA modulator-control unit	A
U0126	Steering angle sensor	A
U0131	EPS control unit	A
U0155	Gauge control module	A
U129D	Precision all wheel steer control unit	A
U129E	Keyless access/TPMS control unit	A

Is it detected normally?

Detected normal

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control unit and the CAN gateway.

U0104: Multipurpose camera unit is Not Available for Bus A

Go to step 5.

U0122: VSA modulator-control unit is Not Available for Bus A

Go to step 5.

U0126: Steering angle sensor is Not Available for Bus A

Go to step 5.

U0131: EPS control unit is Not Available for Bus A

Go to step 5

U0155: Gauge control module is Not Available for Bus A

Go to step 5.

U129D: Precision all wheel steer control unit is Not Available for Bus A

Go to step 5.

U129E: Keyless access/TPMS control unit is Not Available for Bus A

Go to step 5.

Open wire check (F-CAN_H line, F-CAN_L line)

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

- 2. According to the detected DTC on the following table, disconnect the transmitting control unit connector (s).

DTC	Connector
-	CAN gateway 16P connector
U0104	Multipurpose camera unit 20P connector
U0122	VSA modulator-control unit 38P connector
U0126	Steering angle sensor 4P connector
U0131	EPS control unit connector A (11P)
U0155	Gauge control module connector A (32P)
U129D	Precision all wheel steer control unit connector A (16P)
U129E	Keyless access/TPMS control unit connector C (20P)

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

Test condition	Vehicle OFF (LOCK) mode
	CAN gateway 16P connector: disconnected
	Transmitting control unit connector (s) for indicated DTCs: disconnected

DTC	Circuit name	Test point 1 (Receiving control unit)		Test point 2 (Transmitting control unit)
DTC	Circuit name	Connector	Terminal	Connector	Terminal
U0104	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	Multipurpose camera unit 20P connector	No. 2
U0104	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	Multipurpose camera unit 20P connector	No. 13
U0122	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	VSA modulator-control unit 38P connector - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2018-19)	No. 38
U0122	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11		No. 26
U0126	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	Steering angle sensor 4P connector:	No. 2
U0126	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	Steering angle sensor 4P connector:	No. 3
U0131	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	EPS control unit connector A (11P) - Refer to: EPS Control Unit Connector for Inputs and Outputs (2018-19)	No. 10
U0131	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11		No. 11
U0155	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	Gauge control module connector A (32P) - Refer to: Gauge Control Module Connector for Inputs and Outputs (2018-19)	No. 27
U0155	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11		No. 28
U129D	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	Precision all wheel steer control unit connector A (16P) - Refer to: Precision All Wheel Steer Control Unit Connector for Inputs and Outputs (2018-19)	No. 6
U129D	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11		No. 14

DTC	Circuit name	Test point 1 (Receiving control unit)		Test point 2 (Transmitting control unit)
DTC	Circuit name	Connector	Terminal	Connector	Terminal
U129E	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 13	Keyless access/TPMS control unit connector C (20P) - Refer to: Keyless Access/TPMS Control Unit Connector for Inputs and Outputs (2018-19)	No. 2
U129E	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11		No. 12

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

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

Is there continuity?

YES

The F-CAN_H wire and the F-CAN_L wire are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. According to the detected DTC on the following table, substitute or replace the correspond control unit.

DTC	Operation for transmitting control unit
U0104	Check for poor connections or loose terminals at the CAN gateway and the multipurpose camera unit. Replace the multipurpose camera unit .
U0122	Check for poor connections or loose terminals at the CAN gateway and the VSA modulator-control unit. Replace the VSA modulator-control unit - Refer to: VSA Modulator-Control Unit Removal and Installation .
U0126	Check for poor connections or loose terminals at the CAN gateway and the steering angle sensor. Replace the steering angle sensor .
U0131	Check for poor connections or loose terminals at the CAN gateway and the EPS control unit. Replace the EPS control unit .
U0155	Check for poor connections or loose terminals at the CAN gateway and the gauge control module. Replace the gauge control module .
U129D	Check for poor connections or loose terminals at the CAN gateway and the precision all wheel steer control unit. Replace the precision all wheel steer control unit .
U129E	Check for poor connections or loose terminals at the CAN gateway and the keyless access/TPMS control unit. Replace the keyless access/TPMS control unit .

Repair an open in the F-CAN_H wire or the F-CAN_L wire between the transmitting control unit and the CAN gateway.