MULTIPLEX COMMUNICATION SYSTEM, Diagnostic DTC:B1266, B1267

DTC Code DTC Name
B1266 Short to B+ in Instrument Panel System Communication Bus Malfunction
B1267 Short to GND in Instrument Panel System Communication Bus Malfunction

DESCRIPTION

If a +B short circuit or body ground short circuit is detected on the instrument panel system communication bus (BEAN), the instrument panel system communication bus (BEAN) is disabled and a DTC code is output.

DTC No. DTC Detection Condition Trouble Area
B1266 Instrument panel system communication circuit and +B battery system short

  • Gateway ECU

  • A/C amplifier

  • Clearance warning ECU

  • Combination meter

  • Wire harness or connector
B1267 Instrument panel system communication circuit and body ground short

  • Gateway ECU

  • A/C amplifier

  • Clearance warning ECU

  • Combination meter

  • Wire harness or connector

WIRING DIAGRAM

A0161TUE03

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FOR DTC (COMBINATION METER)


    1. A0162IXE04

      Disconnect the J34 connector.

    2. Turn the engine switch on (IG).

    3. Clear the DTC Click here.

    4. Check for DTCs Click here.

      OK
      DTCs B1266 and B1267 are not output.

    NG

    CHECK FOR DTC (A/C AMPLIFIER) Click here

    OK

    REPLACE COMBINATION METER Click here

  2. CHECK FOR DTC (A/C AMPLIFIER)


    1. A0163FEE03

      Reconnect the J34 connector.

    2. Disconnect the J58 connector.

    3. Turn the engine switch on (IG).

    4. Clear the DTC Click here.

    5. Check for DTCs Click here.

      OK
      DTCs B1266 and B1267 are not output.

    NG

    CHECK HARNESS, CONNECTOR AND EACH ECU Click here

    OK

    REPLACE A/C AMPLIFIER Click here

  3. CHECK HARNESS, CONNECTOR AND EACH ECU


    1. A01622PE01

      Disconnect the J34 connector.

    2. Turn the engine switch on (IG).

    3. Clear the DTC Click here.

    4. Check for DTCs Click here.

      OK
      DTCs B1266 and B1267 are not output.

    5. Proceed to next step based on the inspection result.

      Result
      Result Proceed to
      OK (w/ LEXUS Parking Assist-sensor System) A
      OK (w/o LEXUS Parking Assist-sensor System) B
      NG C

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR (A/C AMPLIFIER - COMBINATION METER)

    C

    CHECK HARNESS AND CONNECTOR (COMBINATION METER - GATEWAY ECU) Click here

    A

  4. CHECK FOR DTC (CLEARANCE WARNING ECU)


    1. Reconnect the J58 and J34 connectors.

    2. A0162K5E03

      Disconnect the Q37 connector.

    3. Turn the engine switch on (IG).

    4. Clear the DTC Click here.

    5. Check for DTCs Click here.

      OK
      DTCs B1266 and B1267 are not output.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (A/C AMPLIFIER - COMBINATION METER)

    OK

    REPLACE CLEARANCE WARNING ECU Click here

  5. CHECK HARNESS AND CONNECTOR (COMBINATION METER - GATEWAY ECU)


    1. A0160KVE02

      Disconnect the J76 and J34 connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      J76-4 (MPI1) - Body ground Always Below 1 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      J76-4 (MPI1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER - GATEWAY ECU)

    OK

  6. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - GATEWAY ECU)


    1. A0160KVE05

      Disconnect the J58 connector.

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

      Standard Voltage
      Tester Connection0 Condition Specified Condition
      J76-13 (MPI2) - Body ground Always Below 11 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      J76-13 (MPI2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (A/C AMPLIFIER - GATEWAY ECU)

    OK

    REPLACE GATEWAY ECU