DTC U0100-00, U0101-00, U0122-00, U0129-00, U0131-00, U0155-00 (Parking and Back-Up Sensor 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 U0100-00 : Lost Communication With The PCM/TCM DTC U0101-00 : Lost Communication With The PCM/TCM DTC U0122-00 : Lost Communication With The VSA Modulator-Control Unit DTC U0129-00 : Lost Communication With The Electric Servo Brake System/Electric Brake Booster System DTC U0131-00 : Lost Communication With The EPS Control Unit DTC U0155-00 : Lost Communication With The Gauge Control Module

NOTE:

If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
According to the detected DTC (s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the parking and back-up sensor control unit.
Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.

DTC Description	DTC
U0100-00 Lost Communication With The PCM/TCM
U0101-00 Lost Communication With The PCM/TCM
U0122-00 Lost Communication With The VSA Modulator-Control Unit
U0129-00 Lost Communication With The Electric Servo Brake System/Electric Brake Booster System
U0131-00 Lost Communication With The EPS Control Unit
U0155-00 Lost Communication With The Gauge Control Module

DTC (Parking and Back-Up Sensor Control Unit)

CAN gateway system DTC check

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

DTC Description	DTC

Is any DTC indicated?

YES

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

Go to step 2.

F-CAN circuit communication check
-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 parking and back-up sensor control unit detect the CAN gateway Bus channels B?

Bus B is Not Available

Go to step 3.

Bus B is Available

Go to step 4.

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

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

-2. Disconnect the following connectors.

CAN gateway 16P connector

Parking and back-up sensor control unit 24P connector

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

Test condition	Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected Parking and back-up sensor control unit 24P connector: disconnected
Test point 1	CAN gateway 16P connector (female terminals) No. 6:
Test point 2	Parking and back-up sensor control unit 24P connector No. 22

Test point 1	CAN gateway 16P connector (female terminals) No. 14:
Test point 2	Parking and back-up sensor control unit 24P connector No. 10

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. Check for poor connections or loose terminals at the CAN gateway and the parking and back-up sensor control unit. If they are OK, replace the original parking and back-up sensor control unit .

Repair an open in F-CAN B_H or F-CAN B_L wire between the CAN gateway and the parking and back-up sensor control unit.

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
U0100-00	PCM	A, B
U0101-00 *1	TCM	A, D
U0101-00 *2	TCM	A
U0122-00	VSA modulator-control unit	A, B
U0129-00	Electric brake booster	A, B
U0131-00	EPS control unit	B
U0155-00	Gauge control module	C

*1: A/T

*2: CVT

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.

U0100-00: PCM is Not Available for Bus A

Go to step 5.

U0100-00: PCM is Not Available for Bus B

Go to step 6.

U0101-00: TCM is Not Available for Bus A

Go to step 5.

U0101-00: TCM is Not Available for Bus D

Go to step 8.

U0122-00: VSA modulator-control unit is Not Available for Bus A

Go to step 5.

U0122-00: VSA modulator-control unit is Not Available for Bus B

Go to step 6.

U0129-00: Electric brake booster is Not Available for Bus A

Go to step 5.

U0129-00: Electric brake booster is Not Available for Bus B

Go to step 6.

U0131-00: EPS control unit is Not Available for Bus B

Go to step 6.

U0155-00: Gauge control module unit is Not Available for Bus C

Go to step 7.

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

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

-2. U0100-00: 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 CAN gateway and transmitting control unit connector (s).

DTC	Connector
-	CAN gateway 16P connector
U0100-00	PCM connector A (50P)
U0101-00 *1	TCM connector A (23P)
U0101-00 *2	TCM 50P connector
U0122-00	VSA modulator-control unit 46P connector
U0129-00	Electric brake booster 26P connector

*1: A/T

*2: CVT

-4. Check for continuity between the receiving control unit and the transmitting control unit on the F-CAN A_H circuit and the F-CAN A_L circuit.

Test condition

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

DTC	Circuit name	Receiving control unit		Transmitting control unit
DTC	Circuit name	Connector	Terminal	Connector	Terminal
U0100-00	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	PCM connector A (50P)	No. 37
U0100-00	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	PCM connector A (50P)	No. 36
U0101-00 *1	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	TCM connector A (23P)	No. 19
U0101-00 *1	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	TCM connector A (23P)	No. 18

*1: A/T

*2: CVT

DTC	Circuit name	Receiving control unit		Transmitting control unit
DTC	Circuit name	Connector	Terminal	Connector	Terminal
U0101-00 *2	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	TCM 50P connector	No. 3
U0101-00 *2	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	TCM 50P connector	No. 11
U0122-00	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	VSA modulator-control unit 46P connector	No. 20
U0122-00	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	VSA modulator-control unit 46P connector	No. 21
U0129-00	F-CAN A_H	CAN gateway 16P connector (female terminals):	No. 3	Electric brake booster 26P connector	No. 26
U0129-00	F-CAN A_L	CAN gateway 16P connector (female terminals):	No. 11	Electric brake booster 26P connector	No. 18

*1: A/T

*2: CVT

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, substitute or replace the control unit based on the instructions (see table).

DTC	Operation for transmitting control unit
U0100-00	Substitute a known-good PCM , then recheck. If DTC U0100-00 goes away after substitution, replace the original PCM .
U0101-00	Substitute a known-good TCM (A/T , CVT ), then recheck. If DTC U0101-00 goes away after substitution, replace the original TCM (A/T , CVT ).
U0122-00	Replace the VSA modulator-control unit .
U0129-00	Replace the Electric brake booster .

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

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

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

-2. U0100-00: 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 CAN gateway and transmitting control unit connector (s).

DTC	Connector
-	CAN gateway 16P connector
U0100-00	PCM connector A (50P)
U0122-00	VSA modulator-control unit 46P connector
U0129-00	Electric brake booster 26P connector
U0131-00	EPS control unit connector B (6P)

-4. Check for continuity between the receiving control unit and the transmitting control unit on the F-CAN B_H circuit and the F-CAN B_L circuit.

Test condition

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

DTC	Circuit name	Receiving control unit		Transmitting control unit
DTC	Circuit name	Connector	Terminal	Connector	Terminal
U0100-00	F-CAN B_H	CAN gateway 16P connector (female terminals):	No. 6	PCM connector A (50P)	No. 39
U0100-00	F-CAN B_L	CAN gateway 16P connector (female terminals):	No. 14	PCM connector A (50P)	No. 38
U0122-00	F-CAN B_H	CAN gateway 16P connector (female terminals):	No. 6	VSA modulator-control unit 46P connector	No. 24
U0122-00	F-CAN B_L	CAN gateway 16P connector (female terminals):	No. 14	VSA modulator-control unit 46P connector	No. 25
U0129-00	F-CAN B_H	CAN gateway 16P connector (female terminals):	No. 6	Electric brake booster 26P connector	No. 19
U0129-00	F-CAN B_L	CAN gateway 16P connector (female terminals):	No. 14	Electric brake booster 26P connector	No. 12
U0131-00	F-CAN B_H	CAN gateway 16P connector (female terminals):	No. 6	EPS control unit connector B (6P)	No. 4
U0131-00	F-CAN B_L	CAN gateway 16P connector (female terminals):	No. 14	EPS control unit connector B (6P)	No. 1

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, substitute or replace the control unit based on the instructions (see table).

DTC	Operation for transmitting control unit
U0100-00	Substitute a known-good PCM , then recheck. If DTC U0100-00 goes away after substitution, replace the original PCM .
U0122-00	Replace the VSA modulator-control unit .
U0129-00	Replace the Electric brake booster .
U0131-00	Replace the EPS control unit (steering gearbox assembly) .

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

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

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

-2. According to the detected DTC on the following table, disconnect the CAN gateway and transmitting control unit connector.

DTC	Connector
-	CAN gateway 16P connector
U0155-00	Gauge control module connector A (32P)

-3. Check for continuity between the receiving control unit and the transmitting control unit on the F-CAN C_H circuit and the F-CAN C_L circuit.

Test condition

Vehicle OFF (LOCK) mode
CAN gateway 16P connector: disconnected
Transmitting control unit connector for indicated DTC: disconnected

DTC	Circuit name	Receiving control unit		Transmitting control unit
DTC	Circuit name	Connector	Terminal	Connector	Terminal
U0155-00	F-CAN C_H	CAN gateway 16P connector (female terminals):	No. 5	Gauge control module connector A (32P)	No. 20
U0155-00	F-CAN C_L	CAN gateway 16P connector (female terminals):	No. 13	Gauge control module connector A (32P)	No. 21

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, substitute or replace the control unit based on the instructions (see table).

DTC	Operation for transmitting control unit
U0155-00	Substitute a known-good gauge control module , then recheck. If DTC U0155-00 goes away after substitution, replace the original gauge control module .

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

Open wire check (F-CAN D_H line, F-CAN D_L line)

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

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

DTC	Connector
-	CAN gateway 16P connector
U0101-00	TCM connector A (23P)

-3. Check for continuity between the receiving control unit and the transmitting control unit on the F-CAN D_H circuit and the F-CAN D_L circuit.

Test condition

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

DTC	Circuit name	Receiving control unit		Transmitting control unit
DTC	Circuit name	Connector	Terminal	Connector	Terminal
U0101-00	F-CAN D_H	CAN gateway 16P connector (female terminals):	No. 7	TCM connector A (23P)	No. 13
U0101-00	F-CAN D_L	CAN gateway 16P connector (female terminals):	No. 15	TCM connector A (23P)	No. 12

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

Is there 1.0 Ω or less?

YES

The F-CAN D_H wire and the F-CAN D_L wire are OK.

According to the detected DTC on the following table, substitute or replace the control unit based on the instructions (see table).

DTC	Operation for transmitting control unit
U0101-00	Substitute a known-good TCM , then recheck. If DTC U0101-00 goes away after substitution, replace the original TCM .

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