LEMON Manuals: Even more car manuals for everyone
Home >> Acura >> 2013 >> TL Base >> Repair and Diagnosis >> Body & Frame >> Windows >> Power Windows >> DTC Troubleshooting >> DTC B1142: Door Multiplex Control Unit Lost Communication With Other Unit (UART communication error)

DTC B1142: Door Multiplex Control Unit Lost Communication With Other Unit (UART communication error)

NOTE:
  • If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).
  • Before troubleshooting, make sure the No. 12 (7.5 A), No. 16 (7.5 A) and No. 24 (20 A) fuses in the driver's under-dash fuse/relay box are OK.
  1. Clear the DTCs with the HDS.
  2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.
  3. Open and close all power windows by using the power window master switch.
  4. Check for DTCs with the HDS.

    Is DTC B1142 indicated? 

    YES  - Go to step 5.

    NO  - Intermittent failure, the system is OK at this time. Check for loose or poor connections.

  5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  6. Disconnect these items:
    • Disconnect the power window master switch 37P connector.
    • Disconnect the front passenger's power window switch 37P connector.
    • Disconnect the moonroof control unit/motor 14P connector.
  7. Check for continuity between power window master switch 37P connector terminal No. 27 and front passenger's power windows switch 37P connector terminal No. 29.
    Fig 1: Checking Continuity Between Power Window Master Switch 37P Connector And Front Passenger's Power Windows Switch 37P Connector
    G08071455Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 8.

    NO  - Repair an open or high resistance in the wire.

  8. Check for continuity between power window master switch 37P connector terminal No. 27 and moonroof control unit 14P connector terminal No. 11.
    Fig 2: Checking Continuity Between Power Window Master Switch 37P Connector And Moonroof Control Unit 14P Connector
    G08071456Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 9.

    NO  - Repair an open or high resistance in the wire.

  9. Check for continuity between power window master switch 37P connector terminal No. 27 and body ground.
    Fig 3: Checking Continuity Between Power Window Master Switch 37P Connector Terminal No. 27 And Body Ground
    G08071457Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair a short to ground in the wire.

    NO  - Go to step 10.

  10. Reconnect the power window master switch 37P connector.
  11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  12. Measure the voltage between power window master switch 37P connector terminal No. 27 and body ground.
    Fig 4: Measuring Voltage Between Power Window Master Switch 37P Connector Terminal No. 27 And Body Ground
    G08071458Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there less than 0.2 V? 

    YES  - Go to the FRONT PASSENGER'S POWER WINDOW SWITCH INPUT TEST , and do the power and ground input tests (see POWER WINDOW MASTER SWITCH INPUT TEST  ). If the tests prove OK, substitute a known good front passenger's power window switch. If the DTC goes away, replace the original front passenger's power window switch (see FRONT PASSENGER'S POWER WINDOW SWITCH REPLACEMENT  ). If the DTC is still present, replace the power window master switch (see POWER WINDOW MASTER SWITCH REPLACEMENT  ).

    NO  - Repair a short to power in the wire.

scientia non olet · About LEMON Manuals