DTC U0100, U0122 (Body Control Module)

WARNING: This page is about a different variant/trim than selected.

DTC U0100 : BCM lost communication with ECM/PCM

DTC U0122 : BCM lost communication with VSA/ABS

NOTE:

If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
Refer to the DTC code shown on the display, and then inspect the connectors and terminals based on the instructions in the table below.
The DTC may be stored due to the grounding failure or the power source failure at the transmitting control unit (the grounding inspection and the power source inspection on each control unit are required prior to this checking process).

DTC Description	DTC
U0100 BCM lost communication with ECM/PCM
U0122 BCM lost communication with VSA/ABS

DTC (Body Control Module)

Problem verification

-1. Clear the DTCs with the HDS.

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

-3. Wait for at least 6 seconds.

-4. Check for DTCs with the HDS.

DTC Description	DTC
U0100 BCM lost communication with ECM/PCM
U0122 BCM lost communication with VSA/ABS

Are any DTCs indicated?

YES

Go to step 2.

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

CAN gateway system DTC check

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

DTC Description	DTC
U0029-00 CAN Gateway F-CAN ch A Bus Off
U0047-00 CAN Gateway F-CAN ch B Bus Off
U0056-00 CAN Gateway F-CAN ch C Bus Off
U0065-00 CAN Gateway F-CAN ch D Bus Off
U0038-00 CAN Gateway F-CAN ch E Bus Off
U3000-49 CAN Gateway Internal Failure

Is DTC U0029-00, U0047-00, U0056-00, U0038-00, and/or U3000-49 indicated?

YES

Go to the troubleshooting for CAN gateway system DTC(s) .

Go to step 3.

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

Does the body control module detect the CAN gateway Bus channels B?

Bus B is Not Available

Go to step 4.

Bus B is Available

Go to step 5.

Open wire check (F-CAN B lines)

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

-2. Disconnect the following connectors.

CAN gateway 16P connector
Body control module connector B (36P)

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

Test condition	Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected Body control module connector B (36P): disconnected
Test point 1	CAN gateway 16P connector (female terminals) No. 6:
Test point 2	Body control module connector B (36P) No. 22

Test point 1	CAN gateway 16P connector (female terminals) No. 14:
Test point 2	Body control module connector B (36P) No. 23

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

Is there 1.0 Ω or less?

YES

The F-CAN B_H and F-CAN B_L wires are OK. Replace the body control module .

Repair an open in F-CAN B_H or F-CAN B_L wire.

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.

F-CAN Bus Connected Unit Check

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
U0100	PCM	A, B, E
U0122	VSA modulator-control unit	B, C

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.

U0100: PCM is Not Available for Bus A

Go to step 6.

U0100: PCM is Not Available for Bus B

Go to step 7.

U0100: PCM is Not Available for Bus E

Go to step 9.

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

Go to step 7.

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

Go to step 8.

Open wire check (F-CAN A lines)

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

-2. U0100: Jump the SCS line with the HDS, and wait more than 1 minute.

SCS short

-3. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

DTC	Connector
-	CAN gateway 16P connector
U0100	PCM connector A (50P)

-4. Measure the resistance 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
U0100	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	PCM connector A (50P)	No. 37
U0100	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	PCM connector A (50P)	No. 36

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

Is there 1.0 Ω or less?

YES

The F-CAN A_H wire and the F-CAN A_L wire are OK. According to the detected DTC on the following table replace the correspond control unit.

DTC	Operation for transmitting control unit
U0100	PCM

Repair an open in F-CAN A_H or F-CAN A_L wire.

Open wire check (F-CAN B lines)

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

-2. U0100: Jump the SCS line with the HDS, and wait more than 1 minute.

SCS short

-3. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

DTC	Connector
-	CAN gateway 16P connector
U0100	PCM connector A (50P)
U0122	VSA modulator-control unit 46P connector

-4. Measure the resistance 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
U0100	F-CAN B_H	CAN gateway 16P connector (female terminals):	No. 6	PCM connector A (50P)	No. 39
U0100	F-CAN B_L	CAN gateway 16P connector (female terminals):	No. 14	PCM connector A (50P)	No. 38
U0122	F-CAN B_H	CAN gateway 16P connector (female terminals):	No. 6	VSA modulator-control unit 46P connector	No. 40
U0122	F-CAN B_L	CAN gateway 16P connector (female terminals):	No. 14	VSA modulator-control unit 46P connector	No. 28

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

Is there 1.0 Ω or less?

YES

The F-CAN B_H wire and the F-CAN B_L wire are OK. According to the detected DTC on the following table replace the correspond control unit.

DTC	Operation for transmitting control unit
U0100	PCM
U0122	VSA modulator-control unit

Repair an open in F-CAN B_H or F-CAN B_L wire.

Open wire check (F-CAN C lines)

-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
U0122	VSA modulator-control unit 46P connector

-3. Measure the resistance 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
U0122	F-CAN C_H	CAN gateway 16P connector (female terminals):	No. 5	VSA modulator-control unit 46P connector	No. 46
U0122	F-CAN C_L	CAN gateway 16P connector (female terminals):	No. 13	VSA modulator-control unit 46P connector	No. 34

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

Is there 1.0 Ω or less?

YES

The F-CAN C_H wire and the F-CAN C_L wire are OK. According to the detected DTC on the following table replace the correspond control unit.

DTC	Operation for transmitting control unit
U0122	VSA modulator-control unit

Repair an open in F-CAN C_H or F-CAN C_L wire.

Open wire check (EP-CAN A lines)

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

-2. U0100: Jump the SCS line with the HDS, and wait more than 1 minute.

SCS short

-3. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

DTC	Connector
-	CAN gateway 16P connector
U0100	PCM connector A (50P)

-4. Measure the resistance 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
U0100	EP-CAN A_H	CAN gateway 16P connector (female terminals):	No. 16	PCM connector A (50P)	No. 21
U0100	EP-CAN A_L	CAN gateway 16P connector (female terminals):	No. 8	PCM connector A (50P)	No. 20

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

Is there 1.0 Ω or less?

YES

The EP-CAN A_H wire and the EP-CAN A_L wire are OK. According to the detected DTC on the following table replace the correspond control unit.

DTC	Operation for transmitting control unit
U0100	PCM

Repair an open in EP-CAN A_H or EP-CAN A_L wire.