CAN COMMUNICATION SYSTEM(w/o Toyota Safety Sense), 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


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 junction connector LH
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 junction connector LH
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 junction connector LH

Tech Tips

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

WIRING DIAGRAM

A01V1N0E01

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the ignition 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 ignition 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 ignition switch to ON (IG) and wait at least 60 seconds.

  • After the repair, perform Communication Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • Operating the ignition 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. Check if Hybrid Control of the power management control ECU outputs only DTC U0129.

      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
      Result Proceed to

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

      (GTS display: Hybrid Control)

      		 A

      The power management control ECU 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. A01UXMUE02
      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
      F56-31 (CA3P) - F56-30 (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
      F56-31 (CA3P) - F55-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      F56-30 (CA3N) - F55-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Below 200 Ω: CANL ground short

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      F56-31 (CA3P) - F56-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      F56-30 (CA3N) - F56-7 (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

    A

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    C

    CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU - CAN J/C LH) Click here

    D

    CHECK FOR SHORT IN SUB BUS 15 LINES (CAN J/C LH) Click here

    B

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


    1. A01V125E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F56-31 (CA3P) - F56-30 (CA3N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    NG

  4. CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (CAN J/C LH)


    1. Reconnect the F56 power management control ECU connector.

    2. A01UYJ3E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector LH (Instrument Panel Wire Side))
      *b to Power Management Control ECU

      Disconnect the CAN junction connector LH (instrument panel wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      F62-10 (CANH) - F62-21 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN J/C LH)

    OK

  5. CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (CAN J/C LH)


    1. Reconnect the F62 CAN junction connector LH (instrument panel wire side).

    2. A01UY7YE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector LH (Engine Room Main Wire Side))
      *b to ECM

      Disconnect the CAN junction connector LH (engine room main wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A34-3 (CANH) - A34-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω ECM

    OK

    REPLACE CAN JUNCTION CONNECTOR LH

    NG

  6. CHECK FOR OPEN IN SUB BUS 15 MAIN LINES (ECM - CAN J/C LH)


    1. Reconnect the A34 CAN junction connector LH (engine room main wire side).

    2. A01UYW1E03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A28-12 (CANP) - A28-25 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - CAN J/C LH)

  7. CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU - CAN J/C LH)


    1. A01V125E03
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F56-31 (CA3P) - F56-30 (CA3N) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    NG

  8. CHECK FOR SHORT IN SUB BUS 15 LINES (CAN J/C LH)


    1. Reconnect the F56 power management control ECU connector.

    2. A01UYJ3E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector LH (Instrument Panel Wire Side))
      *b to Power Management Control ECU

      Disconnect the CAN junction connector LH (instrument panel wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      F62-10 (CANH) - F62-21 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Power management control ECU

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN J/C LH)

    OK

  9. CHECK FOR SHORT IN SUB BUS 15 LINES (CAN J/C LH)


    1. Reconnect the F62 CAN junction connector LH (instrument panel wire side).

    2. A01UZGZE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN Junction Connector LH (Engine Room Main Wire Side))
      *b to Brake Booster with Master Cylinder Assembly (skid control ECU)
      *c to ECM

      Disconnect the CAN junction connector LH (engine room main wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A34-1 (CANH) - A34-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Brake booster with master cylinder assembly (skid control ECU)
      A34-3 (CANH) - A34-14 (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 ECM CAN main bus line) B
      NG (Short circuit between bus lines in brake booster with master cylinder assembly (skid control ECU) CAN branch line) C

    A

    REPLACE CAN JUNCTION CONNECTOR LH

    C

    CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - CAN J/C LH) Click here

    B

  10. CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - CAN J/C LH)


    1. Reconnect the A34 CAN junction connector LH (engine room main wire side).

    2. A01UYW1E03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A28-12 (CANP) - A28-25 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - CAN J/C LH)

  11. CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - CAN J/C LH)


    1. Reconnect the A34 CAN junction connector LH (engine room main wire side).

    2. A01UZ9SE01
      Text in Illustration
      *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.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A29-35 (CA2H) - A29-34 (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 BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    C

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - CAN J/C LH)

  12. CHECK FOR SHORT IN SUB BUS 15 LINES (CAN J/C LH)


    1. A01UZDSE02
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN Junction Connector LH (Instrument Panel Wire Side))
      *b to Power Management Control ECU

      Disconnect the CAN junction connector LH (instrument panel wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      F62-10 (CANH) - F3-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Power management control ECU
      F62-21 (CANL) - F3-4 (CG)
      F62-10 (CANH) - F3-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Power management control ECU
      F62-21 (CANL) - F3-16 (BAT)

      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.


    NG

    CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU - CAN J/C LH) Click here

    OK

  13. CHECK FOR SHORT IN SUB BUS 15 LINES (CAN J/C LH)


    1. A01V12HE02
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to CAN Junction Connector LH (Engine Room Main Wire Side))
      *b to Brake Booster with Master Cylinder Assembly (Skid Control ECU)
      *c to ECM

      Disconnect the CAN junction connector LH (engine room main wire side).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      A34-1 (CANH) - F3-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Brake booster with master cylinder assembly (skid control ECU)
      A34-12 (CANL) - F3-4 (CG)
      A34-3 (CANH) - F3-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher ECM
      A34-14 (CANL) - F3-4 (CG)
      A34-1 (CANH) - F3-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Brake booster with master cylinder assembly (skid control ECU)
      A34-12 (CANL) - F3-16 (BAT)
      A34-3 (CANH) - F3-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher ECM
      A34-14 (CANL) - F3-16 (BAT)

      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 (Ground short in ECM CAN main bus line)

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

      		 B

      • 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)

      		 C

    A

    REPLACE CAN JUNCTION CONNECTOR LH

    B

    CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - CAN J/C LH) Click here

    C

    CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER - CAN J/C LH) Click here

  14. CHECK FOR SHORT IN SUB BUS 15 LINES (POWER MANAGEMENT CONTROL ECU - CAN J/C LH)


    1. A01UXHHE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      Disconnect the power management control ECU connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F56-31 (CA3P) - F55-6 (E1) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      F56-30 (CA3N) - F55-6 (E1)
      F56-31 (CA3P) - F56-7 (AM21) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      F56-30 (CA3N) - F56-7 (AM21)

      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.


    OK

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - CAN J/C LH)

  15. CHECK FOR SHORT IN SUB BUS 15 LINES (ECM - CAN J/C LH)


    1. A01V1L5E01
      Text in Illustration
      *A for LHD
      *B for RHD
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition

      A28-12 (CANP) - C9-16 (E1)*1

      A28-12 (CANP) - C10-16 (E1)*2

      		 Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher

      A28-25 (CANN) - C9-16 (E1)*1

      A28-25 (CANN) - C10-16 (E1)*2
      A28-12 (CANP) - A28-1 (BATT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      A28-25 (CANN) - A28-1 (BATT)

      *1: for LHD

      *2: for RHD

      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.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - CAN J/C LH)

  16. CHECK FOR SHORT IN SUB BUS 15 LINES (BRAKE BOOSTER WITH MASTER CYLINDER - CAN J/C LH)


    1. A01V00EE02
      Text in Illustration
      *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.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A29-35 (CA2H) - A29-28 (GND) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      A29-34 (CA2L) - A29-28 (GND)
      A29-35 (CA2H) - A29-14 (BI) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      A29-34 (CA2L) - A29-14 (BI)

      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 BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    C

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY - CAN J/C LH)