CAN COMMUNICATION SYSTEM(for RHD), Diagnostic DTC:U0100,U0129 and U0293

DTC Code	DTC Name
U0100	Lost Communication with ECM / PCM "A"
U0129	Lost Communication with Brake System Control Module
U0293	Lost Communication with Hybrid Vehicle Control System

DESCRIPTION

The hybrid vehicle control ECU communicates with the ECM and brake booster with master cylinder assembly (skid control ECU). When the hybrid vehicle control ECU does not receive data from the ECM or brake booster with master cylinder assembly (skid control ECU), the hybrid vehicle control ECU stores DTC U0100 or U0129.
The ECM communicates with the hybrid vehicle control ECU. When the ECM does not receive data from the hybrid vehicle control ECU, the ECM stores DTC U0293.
The brake booster with master cylinder assembly (skid control ECU) communicates with the hybrid vehicle control ECU. When the brake booster with master cylinder assembly (skid control ECU) does not receive data from the hybrid vehicle control ECU, the brake booster with master cylinder assembly (skid control ECU) stores DTC U0293.


DTC No.	Detection Item	DTC Detection Condition	Trouble Area	DTC Output from
U0100	Lost Communication with ECM / PCM "A"	The hybrid vehicle control ECU does not receive data from the ECM.	Open or short in sub bus 15 main wire or connector Open or short in sub bus 15 branch wire or connector Power source circuit of hybrid vehicle control ECU Hybrid vehicle control ECU ground circuit Hybrid vehicle control ECU Power source circuit of ECM ECM ground circuit ECM No. 36 junction connector	Hybrid vehicle control ECU
U0129	Lost Communication with Brake System Control Module	The hybrid vehicle control ECU does not receive data from the brake booster with master cylinder assembly (skid control ECU).	Open or short in sub bus 15 main wire or connector Open or short in sub bus 15 branch wire or connector Power source circuit of hybrid vehicle control ECU Hybrid vehicle control ECU ground circuit Hybrid vehicle control ECU Power source circuit of brake booster with master cylinder assembly (skid control ECU) Brake booster with master cylinder assembly (skid control ECU) ground circuit Brake booster with master cylinder assembly (skid control ECU) No. 36 junction connector	Hybrid vehicle control ECU
U0293	Lost Communication with Hybrid Vehicle Control System	The ECM does not receive data from the hybrid vehicle control ECU. The brake booster with master cylinder assembly (skid control ECU) does not receive data from the hybrid vehicle control ECU.	Open or short in sub bus 15 main wire or connector Open or short in sub bus 15 branch wire or connector Power source circuit of ECM ECM ground circuit ECM Power source circuit of hybrid vehicle control ECU Hybrid vehicle control ECU ground circuit Hybrid vehicle control ECU Power source circuit of brake booster with master cylinder assembly (skid control ECU) Brake booster with master cylinder assembly (skid control ECU) ground circuit Brake booster with master cylinder assembly (skid control ECU) No. 36 junction connector	ECM Brake booster with master cylinder assembly (skid control ECU)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

Note:

Before measuring the resistance of the CAN bus, turn the power switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.
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Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.
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DTC check procedure: Turn the power switch on (IG) and wait at least 60 seconds.
After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed.
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Tip:

Operating the power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

CHECK FOR DTC

Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Tip:
If the hybrid vehicle control ECU outputs only DTC U0129, troubleshoot DTC U0129 and check the branch circuit of sub bus 15.

Result


Result	Proceed to
The hybrid vehicle control ECU outputs DTC U0129 and other DTCs.	A
The hybrid vehicle control ECU outputs only DTC U0129.	B

GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC

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CHECK SUB BUS 15

Disconnect the cable from the negative (-) auxiliary battery terminal.

*a	Component with harness connected (Hybrid Vehicle Control ECU)	*b	Front view of DLC3

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition	Result
G194-31 (CA3P) - G194-30 (CA3N)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω	Below 53 Ω: Short in line
G194-31 (CA3P) - G194-30 (CA3N)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω	70 Ω or higher: Open in CAN main bus line
G194-31 (CA3P) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Below 200 Ω: Ground short
G194-30 (CA3N) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Below 200 Ω: Ground short
G194-31 (CA3P) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher	Below 6 kΩ: +B short
G194-30 (CA3N) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher	Below 6 kΩ: +B short

Result


Result	Proceed to
OK	A
NG - Open in CAN main wire	B
NG - Short in CAN bus wire	C
NG - +B short - Ground short	D

REPLACE HYBRID VEHICLE CONTROL ECU

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CHECK FOR SHORT IN CAN BUS WIRES (HYBRID VEHICLE CONTROL ECU)Click here

CHECK FOR SHORT IN CAN BUS WIRES (NO. 36 JUNCTION CONNECTOR)Click here

CHECK FOR OPEN IN CAN BUS MAIN WIRE (HYBRID VEHICLE CONTROL ECU)

*a	Front view of wire harness connector (to Hybrid Vehicle Control ECU)

Disconnect the hybrid vehicle control ECU connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
G194-31 (CA3P) - G194-30 (CA3N)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

Result


Proceed to Proceed to
OK
NG

REPLACE HYBRID VEHICLE CONTROL ECU

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CONNECT CONNECTOR

Reconnect the G194 hybrid vehicle control ECU connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 36 JUNCTION CONNECTOR)

*a	Rear view of wire harness connector (to No. 36 Junction Connector)
*b	to ECM
*c	to Hybrid Vehicle Control ECU

Disconnect the No. 36 junction connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
A94-9 (CANH) - A94-20 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω
A94-11 (CANH) - A94-22 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

Result


Result	Proceed to
OK	A
NG (to hybrid vehicle control ECU CAN main wire)	B
NG (to ECM CAN main wire)	C

REPLACE NO. 36 JUNCTION CONNECTOR

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 36 JUNCTION CONNECTOR - HYBRID VEHICLE CONTROL ECU)

CONNECT CONNECTOR

Reconnect the A94 No. 36 junction connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM)

*a	Front view of wire harness connector (to ECM)

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
A62-12 (CANP) - A62-25 (CANN)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

Result


Proceed to Proceed to
OK
NG

REPLACE ECM

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REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (ECM - NO. 36 JUNCTION CONNECTOR)

CHECK FOR SHORT IN CAN BUS WIRES (HYBRID VEHICLE CONTROL ECU)

*a	Front view of wire harness connector (to Hybrid Vehicle Control ECU)

Disconnect the hybrid vehicle control ECU connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
G194-31 (CA3P) - G194-30 (CA3N)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

Result


Proceed to Proceed to
OK
NG

REPLACE HYBRID VEHICLE CONTROL ECU

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CONNECT CONNECTOR

Reconnect the G194 hybrid vehicle control ECU connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR SHORT IN CAN BUS WIRES (NO. 36 JUNCTION CONNECTOR)

*a	Rear view of wire harness connector (to No. 36 Junction Connector)
*b	to ECM
*c	to Brake Booster with Master Cylinder Assembly (Skid Control ECU)
*d	to Hybrid Vehicle Control ECU

Disconnect the No. 36 junction connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition	Connected to
A94-9 (CANH) - A94-20 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω	ECM
A94-10 (CANH) - A94-21 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Brake Booster with Master Cylinder Assembly (Skid Control ECU)
A94-11 (CANH) - A94-22 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω	Hybrid Vehicle Control ECU

Result


Result	Proceed to
OK	A
NG (to hybrid vehicle control ECU CAN main wire)	B
NG (to ECM CAN main wire)	C
NG (to brake booster with master cylinder assembly [skid control ECU] CAN branch wire)	D

REPLACE NO. 36 JUNCTION CONNECTOR

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 36 JUNCTION CONNECTOR - HYBRID VEHICLE CONTROL ECU)

CONNECT CONNECTORClick here

CONNECT CONNECTOR

Reconnect the A94 No. 36 junction connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR SHORT IN CAN BUS WIRES (ECM)

*a	Front view of wire harness connector (to ECM)

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
A62-12 (CANP) - A62-25 (CANN)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

Result


Proceed to Proceed to
OK
NG

REPLACE ECM

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REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (ECM - NO. 36 JUNCTION CONNECTOR)

CONNECT CONNECTOR

Reconnect the A94 No. 36 junction connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU)

*a	Front view of wire harness connector (to Brake Booster with Master Cylinder Assembly [Skid Control ECU])

Disconnect the brake booster with master cylinder assembly (skid control ECU) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
A110-35 (CA2H) - A110-34 (CA2L)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

Result


Proceed to Proceed to
OK
NG

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU)

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REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (SKID CONTROL ECU - NO. 36 JUNCTION CONNECTOR)

CHECK FOR SHORT IN CAN BUS WIRES (NO. 36 JUNCTION CONNECTOR)

Disconnect the No. 36 junction connector.

*a	Rear view of wire harness connector (to No. 36 Junction Connector)	*b	Front view of DLC3
*c	to ECM	*d	to Brake Booster with Master Cylinder Assembly (Skid Control ECU)
*e	to Hybrid Vehicle Control ECU	-	-

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition	Connected to
A94-9 (CANH) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	ECM
A94-20 (CANL) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A94-9 (CANH) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A94-20 (CANL) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A94-10 (CANH) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Brake Booster with Master Cylinder Assembly (Skid Control ECU)
A94-21 (CANL) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A94-10 (CANH) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A94-21 (CANL) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A94-11 (CANH) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Hybrid Vehicle Control ECU
A94-22 (CANL) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A94-11 (CANH) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A94-22 (CANL) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher

Result


Result	Proceed to
OK	A
NG (to hybrid vehicle control ECU CAN main wire)	B
NG (to ECM CAN main wire)	C
NG (to brake booster with master cylinder assembly [skid control ECU] CAN branch wire)	D

REPLACE NO. 36 JUNCTION CONNECTOR

CONNECT CONNECTORClick here

CONNECT CONNECTOR

Reconnect the A94 No. 36 junction connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR SHORT IN CAN BUS WIRES (HYBRID VEHICLE CONTROL ECU)

Disconnect the hybrid vehicle control ECU connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
G194-31 (CA3P) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
G194-30 (CA3N) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
G194-31 (CA3P) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
G194-30 (CA3N) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher

Result


Proceed to Proceed to
OK
NG

REPLACE HYBRID VEHICLE CONTROL ECU

Click here

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (HYBRID VEHICLE CONTROL ECU - NO. 36 JUNCTION CONNECTOR)

CONNECT CONNECTOR

Reconnect the A94 No. 36 junction connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR SHORT IN CAN BUS WIRES (ECM)

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
A62-12 (CANP) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A62-25 (CANN) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A62-12 (CANP) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A62-25 (CANN) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher

Result


Proceed to Proceed to
OK
NG

REPLACE ECM

Click here

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (ECM - NO. 36 JUNCTION CONNECTOR)

CONNECT CONNECTOR

Reconnect the A94 No. 36 junction connector.

Result


Proceed to Proceed to
NEXT

CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU)

Disconnect the brake booster with master cylinder assembly (skid control ECU) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance


Tester Connection	Condition	Specified Condition
A110-35 (CA2H) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A110-34 (CA2L) - G14-4 (CG)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A110-35 (CA2H) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A110-34 (CA2L) - G14-16 (BAT)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher

Result


Proceed to Proceed to
OK
NG

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU)

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REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (SKID CONTROL ECU - NO. 36 JUNCTION CONNECTOR)