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DTC B1000: Communication Bus Line Error

  1. Clear the DTCs with the HDS.
  2. Turn the ignition switch OFF, and then back ON (II).
  3. Wait for 6 seconds or more.
  4. Check for DTCs with the HDS.

    Is DTC B1000 indicated? 

    1. YES  - Go to step  5.
    2. NO  - Intermittent failure. The communication bus line is OK at this time. Check for loose or poor connections, or worn/shorted wires. If the connections are good, check the battery condition (see BATTERY TEST ) and the charging system.
  5. Check for DTCs with the HDS.

    Are DTCs B1005, B1006, B1007, B1008, B1010, and B1011 also indicated ? 

    1. YES  - Go to step  6.
    2. NO  - Faulty MICU; replace the under-dash fuse/relay box.
  6. Turn the ignition switch OFF.
  7. Disconnect the appropriate connector at each control unit in the table one at a time. Clear the DTC, then recheck for DTCs after each unit is disconnected.
    GAUGE CONTROL MODULE TABLE

    Control Unit Connector
    Gauge Control Module Connector B (14P)
    Relay Control Module Connector J (10P)
    Door Multiplex Control Unit Power window master switch connector (23P)
    Combination Switch Control Unit Connector (12P)
    HVAC Control Unit/Climate Control Unit Connector (30P)

    Is DTC B1000 indicated with each individual unit disconnected? 

    1. YES  - Go to step  8.
    2. NO  - Check the power and grounds to the control unit that was disconnected when B1000 did not reset. If OK, replace the control unit.
  8. Disconnect all of the appropriate connectors for each of the units in the table.
    GAUGE CONTROL MODULE

    Control Unit Appropriate Connector
    Gauge Control Module Connector B(14P)
    Relay Control Module Connector J (10P)
    Door Multiplex Control Unit Power window master switch connector (23P)
    Combination Switch Control Unit Connector (12P)
    HVAC Control Unit/Climate Control Unit Connector (30P)
  9. Disconnect under-dash fuse/relay box connectors D (17P), J (21P), N (45P), X (39P), and P (30P).
  10. Check for continuity between each of the under-dash fuse/relay box terminals listed in the table and body ground.
    TERMINALS LIST (1 OF 2)

    Connected Control Unit Driver's under-dash fuse/relay box terminal
    Gauge Control Module N28
    Relay Control Module D11
    Door Multiplex Control Unit J4
    Combination Switch Control Unit X27
    HVAC Control Unit Climate Control Unit N22

    Is there continuity? 

    1. YES  - Repair the short to ground in the wire between the under-dash fuse/relay box and the affected control unit.
    2. NO  - Go to step  11.
  11. Check for voltage between each of the under-dash fuse/relay box terminals listed in the table and body ground.
    TERMINALS LIST (2 OF 2)

    Connected Control Unit Driver's under-dash fuse/relay box terminal
    Gauge Control Module N28
    Relay Control Module D11
    Door Multiplex Control Unit J4
    Combination Switch Control Unit X27
    HVAC Control Unit/Climate Control Unit N22

    Is there less than 1 V? 

    1. YES  - Replace the under-dash fuse/relay box.
    2. NO  - Repair the short to power in the wire between the under-dash fuse/relay box and the affected control unit.
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