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 Hybrid Vehicle Control System

DESCRIPTION


DTC No. Detection Item DTC Detection Condition Trouble Area Note
U0100 Lost Communication with ECM / PCM "A" The hybrid vehicle control ECU assembly 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

  • Hybrid vehicle control ECU assembly

  • ECM

  • Skid control ECU (brake booster with master cylinder assembly)

  • Open or short in No. 1 CAN junction connector

Tech Tips

As there is no sub bus monitor ECU for sub bus 15, each ECU detects communication stops and stores DTCs.
U0129 Lost Communication with Brake System Control Module The hybrid vehicle control ECU assembly does not receive data from the skid control ECU (brake booster with master cylinder assembly).

  • Open or short in sub bus 15 main line or connector

  • Open or short in sub bus 15 branch line or connector

  • Hybrid vehicle control ECU assembly

  • Skid control ECU (brake booster with master cylinder assembly)

  • ECM

  • Open or short in No. 1 CAN junction connector

Tech Tips

As there is no sub bus monitor ECU for sub bus 15, each ECU detects communication stops and stores DTCs.
U0293 Lost Communication with Hybrid Vehicle Control System

  • The ECM does not receive data from the hybrid vehicle control ECU assembly.

  • The skid control ECU (brake booster with master cylinder assembly) does not receive data from the hybrid vehicle control ECU assembly.

  • Open or short in sub bus 15 main line or connector

  • Open or short in sub bus 15 branch line or connector

  • ECM

  • Skid control ECU (brake booster with master cylinder assembly)

  • Hybrid vehicle control ECU assembly

  • Open or short in No. 1 CAN junction connector

Tech Tips

As there is no sub bus monitor ECU for sub bus 15, each ECU detects communication stops and stores DTCs.

Tech Tips

This diagnostic procedure is for when DTCs both U0100 and U0293, or all U0100, U0129 and U0293 are output at the same time.

WIRING DIAGRAM

A01KRKGE16

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 or any 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.

  • After the repair, perform the 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


  1. RECONFIRM DTC OUTPUT


    1. Reconfirm DTCs.


      Powertrain > Hybrid Control > Trouble Codes

      Tech Tips

      If the hybrid vehicle control ECU assembly 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 assembly outputs DTC U0129 and other DTCs.

      (GTS display: Hybrid Control)

      		 A

      The hybrid vehicle control ECU assembly outputs only DTC U0129.

      (GTS display: Hybrid Control)

      		 B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  2. CHECK SUB BUS 15


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

    2. A01KSRPC59
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      E136-31 (CA3P) - E136-30 (CA3N) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Below 54 Ω: Short circuit between bus lines
      70 Ω or higher: Open circuit in a main bus line
      E136-31 (CA3P) - E136-4 (E12) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH short to ground
      E136-30 (CA3N) - E136-4 (E12) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL short to ground
      E136-31 (CA3P) - E136-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      E136-30 (CA3N) - E136-7 (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 hybrid vehicle control ECU assembly.

      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG (Open circuit in CAN main bus line) C
      NG (Short circuit between bus lines) D

      • NG (Short to ground)

      • NG (+B short)

      		 E

    A

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    B

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    D

    CHECK FOR SHORT IN SUB BUS 15 LINES (HYBRID VEHICLE CONTROL ECU ASSEMBLY) Click here

    E

    CHECK FOR SHORT IN SUB BUS 15 LINES (NO. 1 CAN JUNCTION CONNECTOR) Click here

    C

  3. CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (HYBRID VEHICLE CONTROL ECU ASSEMBLY)


    1. Disconnect the E136 hybrid vehicle control ECU assembly connector.

    2. A01KU2BC89
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E136-31 (CA3P) - E136-30 (CA3N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    B

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    C

  4. CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the E136 hybrid vehicle control ECU assembly connector.

    2. Disconnect the A32 No. 1 CAN junction connector.

    3. A01KTAAC01
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)
      *b to Hybrid Vehicle Control ECU Assembly
      *c to ECM

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A32-1 (CANH) - A32-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Hybrid vehicle control ECU assembly
      A32-3 (CANH) - A32-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω ECM
      Result
      Result Proceed to
      OK A
      NG (Open circuit in hybrid vehicle control ECU assembly CAN main bus line) B
      NG (Open circuit in ECM CAN main bus line) C

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - NO. 1 CAN JUNCTION CONNECTOR)

    C

  5. CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (ECM - NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the A32 No. 1 CAN junction connector.

    2. Disconnect the A142 ECM connector.

    3. A01KRMZC39
      *a

      Front view of wire harness connector

      (to ECM)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A142-12 (CANP) - A142-25 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - NO. 1 CAN JUNCTION CONNECTOR)

  6. CHECK FOR SHORT IN SUB BUS 15 LINES (HYBRID VEHICLE CONTROL ECU ASSEMBLY)


    1. Disconnect the E136 hybrid vehicle control ECU assembly connector.

    2. A01KU2BC90
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E136-31 (CA3P) - E136-30 (CA3N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    B

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    C

  7. CHECK FOR SHORT IN SUB BUS 15 LINES (NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the E136 hybrid vehicle control ECU assembly connector.

    2. Disconnect the A32 No. 1 CAN junction connector.

    3. A01KTAAC02
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)
      *b to Hybrid Vehicle Control ECU Assembly
      *c to Skid Control ECU (Brake Booster with Master Cylinder Assembly)
      *d to ECM

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A32-1 (CANH) - A32-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Hybrid vehicle control ECU assembly
      A32-2 (CANH) - A32-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Skid control ECU (brake booster with master cylinder assembly)
      A32-3 (CANH) - A32-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω ECM
      Result
      Result Proceed to
      OK A
      NG (Short circuit between bus lines in hybrid vehicle control ECU assembly 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 skid control ECU (brake booster with master cylinder assembly) CAN branch line) D

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - NO. 1 CAN JUNCTION CONNECTOR)

    D

    CHECK FOR SHORT IN SUB BUS 15 LINES (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - NO. 1 CAN JUNCTION CONNECTOR) Click here

    C

  8. CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the A32 No. 1 CAN junction connector.

    2. Disconnect the A142 ECM connector.

    3. A01KRMZC40
      *a

      Front view of wire harness connector

      (to ECM)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A142-12 (CANP) - A142-25 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω
      Result
      Result
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - NO. 1 CAN JUNCTION CONNECTOR)

  9. CHECK FOR SHORT IN SUB BUS 15 LINES (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - NO. 1 CAN JUNCTION CONNECTOR)


    1. Reconnect the A32 No. 1 CAN junction connector.

    2. Disconnect the A144 skid control ECU (brake booster with master cylinder assembly) connector.

    3. A01KRXWC01
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A144-35 (CA2H) - A144-34 (CA2L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

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

    B

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

    C

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - NO. 1 CAN JUNCTION CONNECTOR)

  10. CHECK FOR SHORT IN SUB BUS 15 LINES (NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the A32 No. 1 CAN junction connector.

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

      A01KT0IC03
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 1 CAN Junction Connector)

      		 *b to Hybrid Vehicle Control ECU Assembly
      *c to Skid Control ECU (Brake Booster with Master Cylinder Assembly) *d to ECM
      Standard Resistance
      Tester Connection Condition Specified Condition Purpose Connected to
      A32-1 (CANH) - E11-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANH short to ground Hybrid vehicle control ECU assembly
      A32-12 (CANL) - E11-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANL short to ground
      A32-2 (CANH) - E11-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANH short to ground Skid control ECU (brake booster with master cylinder assembly)
      A32-13 (CANL) - E11-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANL short to ground
      A32-3 (CANH) - E11-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANH short to ground ECM
      A32-14 (CANL) - E11-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Inspection for CANL short to ground
      A32-1 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short Hybrid vehicle control ECU assembly
      A32-12 (CANL) - E11-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANL +B short
      A32-2 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short Skid control ECU (brake booster with master cylinder assembly)
      A32-13 (CANL) - E11-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANL +B short
      A32-3 (CANH) - E11-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANH +B short ECM
      A32-14 (CANL) - E11-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Inspection for CANL +B short

      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.

      Result
      Result Proceed to
      OK A

      • NG (Short to ground in hybrid vehicle control ECU assembly CAN main bus line)

      • NG (+B short in hybrid vehicle control ECU assembly CAN main bus line)

      		 B

      • NG (Short to ground in ECM CAN main bus line)

      • NG (+B short in ECM CAN main bus line)

      		 C

      • NG (Short to ground in skid control ECU (brake booster with master cylinder assembly) CAN branch line)

      • NG (+B short in skid control ECU (brake booster with master cylinder assembly) CAN branch line)

      		 D

    A

    REPLACE NO. 1 CAN JUNCTION CONNECTOR

    C

    CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - NO. 1 CAN JUNCTION CONNECTOR) Click here

    D

    CHECK FOR SHORT IN SUB BUS 15 LINES (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - NO. 1 CAN JUNCTION CONNECTOR) Click here

    B

  11. CHECK FOR SHORT IN SUB BUS 15 LINES (HYBRID VEHICLE CONTROL ECU ASSEMBLY - NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the E136 hybrid vehicle control ECU assembly connector.

    2. A01KU2BC91
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Purpose Specified Condition
      E136-31 (CA3P) - E136-4 (E12) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANH short to ground 200 Ω or higher
      E136-30 (CA3N) - E136-4 (E12) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANL short to ground
      E136-31 (CA3P) - E136-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANH +B short 6 kΩ or higher
      E136-30 (CA3N) - E136-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANL +B short

      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.

      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    B

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    C

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - NO. 1 CAN JUNCTION CONNECTOR)

  12. CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the A142 ECM connector.

    2. A01KRGNC03
      *a

      Front view of wire harness connector

      (to ECM)

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

      Standard Resistance
      Tester Connection Condition Purpose Specified Condition
      A142-12 (CANP) - B178-16 (E1) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANH short to ground 200 Ω or higher
      A142-25 (CANN) - B178-16 (E1) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANL short to ground
      A142-12 (CANP) - A142-1 (BATT) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANH +B short 6 kΩ or higher
      A142-25 (CANN) - A142-1 (BATT) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANL +B short

      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.

      Result
      Result
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - NO. 1 CAN JUNCTION CONNECTOR)

  13. CHECK FOR SHORT IN SUB BUS 15 LINES (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - NO. 1 CAN JUNCTION CONNECTOR)


    1. Disconnect the A144 skid control ECU (brake booster with master cylinder assembly) connector.

    2. A01KTPBC01
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

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

      Standard Resistance
      Tester Connection Condition Purpose Specified Condition
      A144-35 (CA2H) - A144-28 (GND) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANH short to ground 200 Ω or higher
      A144-34 (CA2L) - A144-28 (GND) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANL short to ground
      A144-35 (CA2H) - A144-15 (BS) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANH +B short 6 kΩ or higher
      A144-34 (CA2L) - A144-15 (BS) Cable disconnected from negative (-) auxiliary battery terminal Inspection for CANL +B short

      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.

      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

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

    B

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

    C

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) - NO. 1 CAN JUNCTION CONNECTOR)