CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1108, U1109

DTC Code DTC Name
U1108 Lost Communication with Front Active Stabilizer Control ECU
U1109 Lost Communication with Rear Active Stabilizer Control ECU

DESCRIPTION

DTC No. DTC Detection Condition Trouble Area
U1108 No communication with the front active stabilizer control ECU

  • Open or short in CAN No. 3 bus main wire or connector

  • Open or short in CAN No. 3 bus branch wire or connector

  • Front active stabilizer control ECU

  • Rear active stabilizer control ECU

  • CAN No. 10 junction connector
U1109 No communication with the rear active stabilizer control ECU

  • Open or short in CAN No. 3 bus main wire or connector

  • Open or short in CAN No. 3 bus branch wire or connector

  • Front active stabilizer control ECU

  • Rear active stabilizer control ECU

  • CAN No. 10 junction connector

Tech Tips


  • This diagnosis procedure is for when DTC U1108 or U1109 is output by an active stabilizer control ECU.

  • If DTC U1108 is output by the power management control ECU, refer to Lost Communication with Front Active Stabilizer ECU Click here.

  • If DTC U1109 is output by the power management control ECU, refer to Lost Communication with Rear Active Stabilizer ECU Click here.

WIRING DIAGRAM

A01NFABE01

INSPECTION PROCEDURE

Note


  • Turn the power switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.

  • Turn the power switch off before inspecting CAN bus wires for a ground short.

  • After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.

  • Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

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.

      Tech Tips

      If CAN No. 2 bus DTC U1002 is output from the power management control ECU (Intelligent tester display/PM1 Gateway), troubleshoot for U1002 and check for malfunctions in the CAN No. 2 main bus circuit.

      Result
      Result Proceed to
      U1002 is not output from power management control ECU (Intelligent tester display/PM1 Gateway) A
      U1002 is output from power management control ECU (Intelligent tester display/PM1 Gateway) B

    B

    GO TO CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  2. RECONFIRM DTC OUTPUT


    1. Check that the power management control ECU (Intelligent tester display/PM1 Gateway) does not output DTCs U1108 or U1109.

      Tech Tips

      If DTC U1108 or U1109 is output from the power management control ECU (Intelligent tester display/PM1 Gateway), check for malfunctions between the front and rear active stabilizer control ECUs and the main bus wires of the CAN No. 2 bus.

      Result
      Result Proceed to
      Neither DTC U1108 nor U1109 is output from power management control ECU (Intelligent tester display/PM1 Gateway) A
      DTC U1108 is output from power management control ECU (Intelligent tester display/PM1 Gateway) B
      DTC U1109 is output from power management control ECU (Intelligent tester display/PM1 Gateway) C

    B

    GO TO CIRCUITS INDICATED BY OUTPUT DTCS Click here

    C

    GO TO CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  3. CHECK CAN NO. 3 BUS WIRE


    1. Turn the power switch off.

    2. A01NDO9E35
      Text in Illustration
      *1

      Component with harness connected

      (Skid Control ECU)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Result
      A91-13 (CANH) - A91-12 (CANL) Power switch off 54 to 69 Ω

      Below 54 Ω:

      Short circuit between bus wires

      70 Ω or more:

      Open circuit in a main bus wire
      A91-13 (CANH) - A90-3 (GND2) Power switch off 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      A91-12 (CANL) - A90-3 (GND2) Power switch off 200 Ω or higher

      Below 200 Ω:

      CANL ground short

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      A91-13 (CANH) - A90-4 (+BI1) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      A91-12 (CANL) - A90-4 (+BI1) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short
      Result
      Result Proceed to
      OK A
      Open circuit in CAN main bus wire B
      Short circuit between bus wires C

      • Ground short

      • +B short

      		 D

    B

    CHECK FOR OPEN IN CAN NO. 3 BUS MAIN WIRE (SKID CONTROL ECU MAIN WIRE) Click here

    C

    CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (SKID CONTROL ECU) Click here

    D

    CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (SKID CONTROL ECU) Click here

    A

  4. CHECK FOR OPEN IN CAN NO. 3 BUS BRANCH WIRE (FRONT ACTIVE STABILIZER CONTROL ECU BRANCH WIRE)


    1. A01NGJQE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Front Active Stabilizer Control ECU)

      Turn the power switch off.

    2. Disconnect the front active stabilizer control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      g13-2 (CANH) - g13-3 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN NO. 3 BUS BRANCH WIRE OR CONNECTOR (FRONT ACTIVE STABILIZER CONTROL ECU)

    OK

  5. CHECK FOR OPEN IN CAN NO. 3 BUS BRANCH WIRE (REAR ACTIVE STABILIZER CONTROL ECU BRANCH WIRE)


    1. Turn the power switch off.

    2. A01NGJQE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Rear Active Stabilizer Control ECU)

      Disconnect the rear active stabilizer control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      g12-2 (CANH) - g12-3 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN NO. 3 BUS BRANCH WIRE OR CONNECTOR (REAR ACTIVE STABILIZER CONTROL ECU)

    OK

    REPLACE ACTIVE STABILIZER CONTROL ECU ASSEMBLY Click here

  6. CHECK FOR OPEN IN CAN NO. 3 BUS MAIN WIRE (SKID CONTROL ECU MAIN WIRE)


    1. A01NELCE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

      Disconnect the skid control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A91-13 (CANH) - A91-12 (CANL) Power switch off 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN NO. 3 BUS MAIN WIRE (CAN NO. 10 J/C) Click here

    OK

    REPLACE SKID CONTROL ECU Click here

  7. CHECK FOR OPEN IN CAN NO. 3 BUS MAIN WIRE (CAN NO. 10 J/C)

    Tech Tips

    - The connectors connected to the CAN junction connectors can be distinguished according to the color of the communication bus wires.

    - Reconnecting the connectors to non-specified positions on the CAN junction connectors does not affect system operation. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


    1. Reconnect the skid control ECU connector.

    2. A01NE7AE27
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 10 Junction Connector)
      *2 to Skid Control ECU

      Disconnect the CAN bus main wire connector from the CAN No. 10 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connected
      P59-1 (CANH) - P59-2 (CANL) Power switch off 108 to 132 Ω Skid control ECU

    NG

    REPAIR OR REPLACE CAN NO. 3 BUS MAIN WIRE OR CONNECTOR (CAN NO. 10 J/C - SKID CONTROL ECU)

    OK

    REPLACE CAN NO. 10 JUNCTION CONNECTOR

  8. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (SKID CONTROL ECU)


    1. A01NELCE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

      Disconnect the skid control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A91-13 (CANH) - A91-12 (CANL) Power switch off 108 to 132 Ω

    NG

    CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (CAN J/C NO. 10) Click here

    OK

    REPLACE SKID CONTROL ECU Click here

  9. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (CAN J/C NO. 10)

    Tech Tips

    - The connectors connected to the CAN junction connectors can be distinguished according to the color of the communication bus wires.

    - Reconnecting the connectors to non-specified positions on the CAN junction connectors does not affect system operation. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


    1. Reconnect the skid control ECU connector.

    2. A01NE7AE27
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 10 Junction Connector)
      *2 to Skid Control ECU

      Disconnect the CAN bus main wire connector from the CAN No. 10 junction connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Connected
      P59-1 (CANH) - P59-2 (CANL) Power switch off 108 to 132 Ω Skid control ECU

    NG

    REPAIR OR REPLACE CAN NO. 3 BUS MAIN WIRE OR CONNECTOR (CAN NO. 10 J/C - SKID CONTROL ECU)

    OK

  10. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (CAN J/C NO. 10)

    Tech Tips

    - The connectors connected to the CAN junction connectors can be distinguished according to the color of the communication bus wires.

    - Reconnecting the connectors to non-specified positions on the CAN junction connectors does not affect system operation. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


    1. Reconnect the CAN bus main wire connector to the CAN No. 10 junction connector.

    2. A01NF5WE01

      Disconnect the front active stabilizer control ECU branch wire connector from the CAN No. 10 junction connector.

    3. Disconnect the rear active stabilizer control ECU branch wire connector from the CAN No. 10 junction connector.

    4. A01NDO9E36
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 10 Junction Connector)
      *2 to Front Active Stabilizer Control ECU
      *3 to Rear Active Stabilizer Control ECU
      *4

      Component with harness connector

      (Skid Control ECU)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A91-13 (CANH) - A91-12 (CANL) Power switch off 54 to 69 Ω

    NG

    REPLACE CAN NO. 10 JUNCTION CONNECTOR

    OK

  11. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (FRONT ACTIVE STABILIZER CONTROL ECU BRANCH WIRE)


    1. Turn the power switch off.

    2. Reconnect the front active stabilizer control ECU branch wire to the CAN No. 10 junction connector.

    3. A01NGJQE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Front Active Stabilizer Control ECU)

      Disconnect the front active stabilizer control ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      g13-2 (CANH) - g13-3 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN NO. 3 BUS BRANCH WIRE OR CONNECTOR (FRONT ACTIVE STABILIZER CONTROL ECU)

    OK

  12. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (REAR ACTIVE STABILIZER CONTROL ECU BRANCH WIRE)


    1. Turn the power switch off.

    2. Reconnect the rear active stabilizer control ECU branch wire to the CAN No. 10 junction connector.

    3. A01NGJQE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Rear Active Stabilizer Control ECU)

      Disconnect the rear active stabilizer control ECU connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      g12-2 (CANH) - g12-3 (CANL) Power switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN NO. 3 BUS BRANCH WIRE OR CONNECTOR (REAR ACTIVE STABILIZER CONTROL ECU)

    OK

    REPLACE ACTIVE STABILIZER CONTROL ECU ASSEMBLY Click here

  13. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (SKID CONTROL ECU)


    1. A01NDBHE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

      Disconnect the skid control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      A91-13 (CANH) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANH ground short
      A91-12 (CANL) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANL ground short
      A91-13 (CANH) - A90-4 (+BI1) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A91-12 (CANL) - A90-4 (+BI1) Cable disconnected from negative (-) 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 CAN Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.


    NG

    CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (CAN BUS MAIN WIRE) Click here

    OK

    REPLACE SKID CONTROL ECU Click here

  14. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (CAN BUS MAIN WIRE)

    Tech Tips

    - The connectors connected to the CAN junction connectors can be distinguished according to the color of the communication bus wires.

    - Reconnecting the connectors to non-specified positions on the CAN junction connectors does not affect system operation. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


    1. A01NE7AE27

      Disconnect the CAN bus main wire connector from the CAN No. 10 junction connector.

    2. A01NDBHE03
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 10 Junction Connector)
      *2 to Skid Control ECU
      *3

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      A91-13 (CANH) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANH ground short
      A91-12 (CANL) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANL ground short
      A91-13 (CANH) - A90-4 (+BI1) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A91-12 (CANL) - A90-4 (+BI1) Cable disconnected from negative (-) 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 CAN Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.


    NG

    REPAIR OR REPLACE CAN NO. 3 BUS MAIN WIRE OR CONNECTOR (SKID CONTROL ECU - CAN NO. 10 JUNCTION CONNECTOR)

    OK

  15. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (CAN J/C NO. 10)

    Tech Tips

    - The connectors connected to the CAN junction connectors can be distinguished according to the color of the communication bus wires.

    - Reconnecting the connectors to non-specified positions on the CAN junction connectors does not affect system operation. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


    1. Reconnect the CAN bus main wire connector to the CAN No. 10 junction connector.

    2. A01NF5WE01

      Disconnect the front active stabilizer control ECU branch wire connector from the CAN No. 10 junction connector.

    3. Disconnect the rear active stabilizer control ECU branch wire connector from the CAN No. 10 junction connector.

    4. A01NDBHE04
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to CAN No. 10 Junction Connector)
      *2 to Front Active Stabilizer Control ECU
      *3 to Rear Active Stabilizer Control ECU
      *4

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      A91-13 (CANH) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANH ground short
      A91-12 (CANL) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANL ground short
      A91-13 (CANH) - A90-4 (+BI1) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A91-12 (CANL) - A90-4 (+BI1) Cable disconnected from negative (-) 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 CAN Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.


    NG

    REPLACE CAN NO. 10 JUNCTION CONNECTOR

    OK

  16. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (FRONT ACTIVE STABILIZER CONTROL ECU BRANCH WIRE)


    1. Turn the power switch off.

    2. Reconnect the front active stabilizer control ECU branch wire to the CAN No. 10 junction connector.

    3. A01NGJQE01

      Disconnect the front active stabilizer control ECU connector.

    4. A01NDBHE05
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Front Active Stabilizer Control ECU)
      *2

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      A91-13 (CANH) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANH ground short
      A91-12 (CANL) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANL ground short
      A91-13 (CANH) - A90-4 (+BI1) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A91-12 (CANL) - A90-4 (+BI1) Cable disconnected from negative (-) 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 CAN Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.


    NG

    REPAIR OR REPLACE CAN NO. 3 BUS BRANCH WIRE OR CONNECTOR (FRONT ACTIVE STABILIZER CONTROL ECU)

    OK

  17. CHECK FOR SHORT IN CAN NO. 3 BUS WIRE (REAR ACTIVE STABILIZER CONTROL ECU BRANCH WIRE)


    1. Turn the power switch off.

    2. Reconnect the rear active stabilizer control ECU branch wire to the CAN No. 10 junction connector.

    3. A01NGJQE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Rear Active Stabilizer Control ECU)

      Disconnect the rear active stabilizer control ECU connector.

    4. A01NDBHE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose
      A91-13 (CANH) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANH ground short
      A91-12 (CANL) - A90-3 (GND2) Power switch off 200 Ω or higher Inspection for CANL ground short
      A91-13 (CANH) - A90-4 (+BI1) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short
      A91-12 (CANL) - A90-4 (+BI1) Cable disconnected from negative (-) 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 CAN Bus Wire inspection.

      Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN Bus Wire inspection.


    NG

    REPAIR OR REPLACE CAN NO. 3 BUS BRANCH WIRE OR CONNECTOR (REAR ACTIVE STABILIZER CONTROL ECU)

    OK

    REPLACE ACTIVE STABILIZER CONTROL ECU ASSEMBLY Click here