CAN COMMUNICATION SYSTEM, Diagnostic DTC:U0164

DTC Code DTC Name
U0164 Lost Communication with A/C ECU

DESCRIPTION

DTC No. DTC Detection Condition Trouble Area
U0164 No communication from the air conditioning amplifier assembly continues.

  • Air conditioning amplifier assembly branch wire or connector

  • Power source circuit of air conditioning amplifier assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A01EL23E05

INSPECTION PROCEDURE

Note


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

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

  • After the ignition 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 ignition 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 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. Reconfirm DTCs.

      Tech Tips

      If power management bus DTC U1002 is output from the power management control ECU (GTS display: PM2 Gateway), troubleshoot for U1002 and check for malfunctions in the power management main bus circuit.

      Result
      Result Proceed to
      U1002 is not output from power management control ECU (GTS display: PM2 Gateway) A
      U1002 is output from power management control ECU (GTS display: PM2 Gateway) B

    B

    GO TO CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  2. CHECK FOR OPEN IN CAN BUS WIRES (AIR CONDITIONING AMPLIFIER ASSEMBLY BRANCH WIRE)


    1. Turn the ignition switch off.

    2. A01EJLOE30
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      Disconnect the air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D47-11 (CANH) - D47-12 (CANL) Ignition switch off 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY BRANCH WIRE)

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. Turn the ignition switch to ON.

    2. A01EJLOE31
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D47-1 (IG+) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  4. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. A01EJLOE35
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D47-14 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here