CAN COMMUNICATION SYSTEM, Diagnostic DTC:U0100, U0129, U0293

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

DESCRIPTION

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

DTC No.	DTC Detection Condition	Trouble Area
U0100	The power management control ECU does not receive data from the ECM.	Open or short in sub bus 15 main line or connector Open or short in sub bus 15 branch line or connector Power source circuit of power management control ECU Power management control ECU Power source circuit of ECM ECM Open or short in CAN No. 1 junction connector
U0129	The power management 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 line or connector Open or short in sub bus 15 branch line or connector Power source circuit of power management control ECU Power management control ECU Power source circuit of brake booster with master cylinder assembly (skid control ECU) Brake booster with master cylinder assembly (skid control ECU) Open or short in CAN No. 1 junction connector
U0293	The ECM does not receive data from the power management control ECU. The brake booster with master cylinder assembly (skid control ECU) does not receive data from the power management control ECU.	Open or short in sub bus 15 main line or connector Open or short in sub bus 15 branch line or connector Power source circuit of ECM ECM Power source circuit of power management control ECU Power management control ECU Power source circuit of brake booster with master cylinder assembly (skid control ECU) Brake booster with master cylinder assembly (skid control ECU) Open or short in CAN No. 1 junction connector

Tech Tips

This diagnosis procedure is for when DTC U0100, U0129 and U0293 are output at the same time.

WIRING DIAGRAM

INSPECTION PROCEDURE

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 Click here.
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 Click here.
After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
DTC check procedure: Turn the power switch on (IG) and wait at least 60 seconds.
After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips

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

RECONFIRM DTC OUTPUT

Reconfirm DTCs.

Tech Tips

If the power management control ECU outputs only DTC U0129, troubleshoot DTC U0129 and check the branch circuit of sub bus 15.

Result

Proceed to

The power management control ECU outputs DTC U0129 and other DTCs.

(Techstream display: Hybrid Control)

The power management control ECU outputs only DTC U0129.

(Techstream display: Hybrid Control)

GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

CHECK SUB BUS 15

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

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

Standard Resistance

Tester Connection	Condition	Specified Condition	Result
I4-31 (CA3P) - I4-30 (CA3N)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω	Below 54 Ω: Short circuit between bus lines
I4-31 (CA3P) - I4-30 (CA3N)		54 to 69 Ω	70 Ω or higher: Open circuit in a main bus line
I4-31 (CA3P) - I4-4 (E12)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Below 200 Ω: CANH ground short
I4-30 (CA3N) - I4-4 (E12)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Below 200 Ω: CANL ground short

Text in Illustration
*a	Component with harness connected (Power Management Control ECU)

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

Standard Resistance

Tester Connection	Condition	Specified Condition	Result
I4-31 (CA3P) - I4-7 (AM21)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher	Below 6 kΩ: CANH +B short
I4-30 (CA3N) - I4-7 (AM21)	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher	Below 6 kΩ: CANL +B short

Tech Tips

When the values are as specified, clear and recheck for DTCs. When no DTCs are output, check for malfunctions such as damage or improper connection of the relevant connectors.
If DTCs are output although the bus circuit is normal and DTCs were cleared, replace the power management control ECU.

Result

Result	Proceed to
OK	A
NG (Open circuit in CAN main bus line)	B
NG (Short circuit between bus lines)	C
NG (Ground short) NG (+B short)	D

CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (POWER MANAGEMENT CONTROL ECU) Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU) Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (CAN NO. 1 J/C) Click here

REPLACE POWER MANAGEMENT CONTROL ECU Click here

CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (POWER MANAGEMENT CONTROL ECU)

Disconnect the power management control ECU connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I4-31 (CA3P) - I4-30 (CA3N)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

Text in Illustration
*a	Rear view of wire harness connector (to Power Management Control ECU)

CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (CAN NO. 1 J/C) Click here

REPLACE POWER MANAGEMENT CONTROL ECU Click here

CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (CAN NO. 1 J/C)

Reconnect the power management control ECU connector.
Disconnect the CAN No. 1 junction connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition	Connected to
A72-2 (CANH) - A72-8 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω	ECM
A72-3 (CANH) - A72-9 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω	Power management control ECU

Text in Illustration
*a	Front view of wire harness connector (to CAN No. 1 Junction Connector)
*b	to ECM
*c	to Power Management Control ECU

Result

Result	Proceed to
OK	A
NG (Open circuit in power management control ECU CAN main bus line)	B
NG (Open circuit in ECM CAN main bus line)	C

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 1 J/C)

CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (ECM - CAN NO. 1 J/C) Click here

REPLACE CAN NO. 1 JUNCTION CONNECTOR

CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (ECM - CAN NO. 1 J/C)

Reconnect the CAN No. 1 junction connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A25-12 (CANP) - A25-25 (CANN)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

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

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - CAN NO. 1 J/C)

REPLACE ECM Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU)

Disconnect the power management control ECU connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I4-31 (CA3P) - I4-30 (CA3N)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

Text in Illustration
*a	Rear view of wire harness connector (to Power Management Control ECU)

CHECK FOR SHORT IN SUB BUS 15 LINES (CAN NO. 1 J/C) Click here

REPLACE POWER MANAGEMENT CONTROL ECU Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (CAN NO. 1 J/C)

Reconnect the power management control ECU connector.
Disconnect the CAN No. 1 junction connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition	Connected to
A72-1 (CANH) - A72-7 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Brake booster with master cylinder assembly (skid control ECU)
A72-2 (CANH) - A72-8 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω	ECM
A72-3 (CANH) - A72-9 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω	Power management control ECU

Text in Illustration
*a	Front view of wire harness connector (to CAN No. 1 Junction Connector)
*b	to ECM
*c	to Power Management Control ECU
*d	to Brake Booster with Master Cylinder Assembly (Skid Control ECU)

Result

Result	Proceed to
OK	A
NG (Short circuit between bus lines in power management control ECU CAN main bus line)	B
NG (Short circuit between bus lines in ECM CAN main bus line)	C
NG (Short circuit between bus lines in brake booster with master cylinder assembly (skid control ECU) CAN branch line)	D

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 1 J/C)

CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - CAN NO. 1 J/C) Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 1 J/C) Click here

REPLACE CAN NO. 1 JUNCTION CONNECTOR

CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - CAN NO. 1 J/C)

Reconnect the CAN No. 1 junction connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A25-12 (CANP) - A25-25 (CANN)	Cable disconnected from negative (-) auxiliary battery terminal	108 to 132 Ω

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

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - CAN NO. 1 J/C)

REPLACE ECM Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 1 J/C)

Reconnect the CAN No. 1 junction connector.
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
A28-35 (CA2H) - A28-34 (CA2L)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

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

REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 1 J/C)

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (CAN NO. 1 J/C)

Disconnect the CAN No. 1 junction connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition	Connected to
A72-1 (CANH) - GND	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Brake booster with master cylinder assembly (skid control ECU)
A72-7 (CANL) - GND		200 Ω or higher
A72-2 (CANH) - GND	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	ECM
A72-8 (CANL) - GND		200 Ω or higher	ECM
A72-3 (CANH) - GND	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher	Power management control ECU
A72-9 (CANL) - GND		200 Ω or higher	Power management control ECU
A72-1 (CANH) - +B	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher	Brake booster with master cylinder assembly (skid control ECU)
A72-7 (CANL) - +B		6 kΩ or higher
A72-2 (CANH) - +B	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher	ECM
A72-8 (CANL) - +B		6 kΩ or higher	ECM
A72-3 (CANH) - +B	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher	Power management control ECU
A72-9 (CANL) - +B		6 kΩ or higher	Power management control ECU

Tech Tips

It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 15 inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 15 inspection.

Text in Illustration
*a	Front view of wire harness connector (to CAN No. 1 Junction Connector)
*b	to ECM
*c	to Power Management Control ECU
*d	to Brake Booster with Master Cylinder Assembly (Skid Control ECU)

Result

Result	Proceed to
OK	A
NG (Ground short in power management control ECU CAN main bus line) NG (+B short in power management control ECU CAN main bus line)	B
NG (Ground short in ECM CAN main bus line) NG (+B short in ECM CAN main bus line)	C
NG (Ground short in brake booster with master cylinder assembly (skid control ECU) CAN branch line) NG (+B short in brake booster with master cylinder assembly (skid control ECU) CAN branch line)	D

CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU - CAN NO. 1 J/C) Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - CAN NO. 1 J/C) Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 1 J/C) Click here

REPLACE CAN NO. 1 JUNCTION CONNECTOR

CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU - CAN NO. 1 J/C)

Disconnect the power management control ECU connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I4-31 (CA3P) - GND	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
I4-30 (CA3N) - GND		200 Ω or higher
I4-31 (CA3P) - +B	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
I4-30 (CA3N) - +B		6 kΩ or higher

Tech Tips

It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 15 inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 15 inspection.

Text in Illustration
*a	Rear view of wire harness connector (to Power Management Control ECU)

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN NO. 1 J/C)

REPLACE POWER MANAGEMENT CONTROL ECU Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - CAN NO. 1 J/C)

Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A25-12 (CANP) - GND	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A25-25 (CANN) - GND		200 Ω or higher
A25-12 (CANP) - +B	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A25-25 (CANN) - +B		6 kΩ or higher

Tech Tips

It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 15 inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 15 inspection.

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

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - CAN NO. 1 J/C)

REPLACE ECM Click here

CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 1 J/C)

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
A28-35 (CA2H) - GND	Cable disconnected from negative (-) auxiliary battery terminal	200 Ω or higher
A28-34 (CA2L) - GND		200 Ω or higher
A28-35 (CA2H) - +B	Cable disconnected from negative (-) auxiliary battery terminal	6 kΩ or higher
A28-34 (CA2L) - +B		6 kΩ or higher

Tech Tips

It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 15 inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 15 inspection.

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

REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER - CAN NO. 1 J/C)

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Click here