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Home >> Acura >> 2012 >> ZDX >> Repair and Diagnosis >> Body & Frame >> Seats >> Driver Position Memory System (DPMS) >> DTC Troubleshooting >> DTC B1840: Steering Column Tilt Pulse Failure
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DTC B1840: Steering Column Tilt Pulse Failure

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 ).
  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. Operate the power tilt in each direction with the power tilt/telescopic steering switch.
  4. Check for DTCs with the HDS.

    Is DTC B1840 indicated? 

    YES  -Go to step 5.

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

  5. Clear the DTCs with the HDS. Operate the tilt switch in each direction for at least 1 second, then check for DTCs with the HDS.

    Is DTC B1841 also indicated? 

    YES  -Go to step  17.

    NO  -Go to step 6.

  6. Clear the DTCs with the HDS.
  7. 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.
  8. Operate the tilt switch for at least 2 seconds, and check the tilt motor operation.

    Does the tilt motor run smoothly? 

    YES  -Go to step 9.

    NO  -Go to step  24.

  9. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  10. Disconnect power tilt/telescopic steering control unit connector A (16P).
  11. Disconnect the power tilt motor/position sensor 8P connector.
  12. Check for continuity between power tilt/telescopic steering control unit connector A (16P) terminals No. 4, No. 12, and No. 16 and power tilt motor/position sensor 8P connector terminals No. 6, No. 7, and No. 8 respectively.
    Fig 1: Checking Continuity Between Power Tilt/Telescopic Steering Control Unit Connector A (16P) And Power Tilt Motor/Position Sensor 8P Connector Terminals
    G08077078Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 13.

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

  13. Check for continuity between body ground and power tilt/telescopic steering control unit connector A (16P) terminal No. 4 and No. 12 individually.
    Fig 2: Checking Continuity Between Body Ground And Power Tilt/Telescopic Steering Control Unit Connector A (16P) Terminal 4 And 12
    G08077079Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to ground in the wire(s).

    NO  -Go to step 14.

  14. Reconnect power tilt/telescopic steering control unit connector A (16P).
  15. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  16. Measure the voltage between power tilt motor/position sensor 8P connector terminals No. 6 and No. 8, and between terminals No. 7 and No. 8.
    Fig 3: Measuring Voltage Between Power Tilt Motor/Position Sensor 8P Connector Terminals
    G08077080Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 5 V? 

    YES  -Faulty power tilt position sensor; replace the steering column assembly (see STEERING COLUMN REMOVAL AND INSTALLATION ).

    NO  -If there is no voltage, replace the power tilt/telescopic steering control unit (see POWER TILT/TELESCOPIC STEERING SWITCH TEST/REPLACEMENT  ). If there is battery voltage, repair a short to power in the wires.

  17. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  18. Disconnect power tilt/telescopic steering control unit connector A (16P).
  19. Disconnect the power tilt motor/position sensor 8P connector.
  20. Check for continuity between power tilt/telescopic steering control unit connector A (16P) terminals No. 2 and No. 16 and power tilt motor/position sensor 8P connector terminals No. 5 and No. 8 respectively.
    Fig 4: Checking Continuity Between Power Tilt/Telescopic Steering Control Unit Connector A (16P) And Power Tilt Motor/Position Sensor 8P Connector Terminals
    G08077081Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 21.

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

  21. Reconnect power tilt/telescopic steering control unit connector A (16P).
  22. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  23. Measure the voltage between power tilt/telescopic steering control unit connector A (16P) terminals No. 2 and No. 16.
    Fig 5: Measuring Voltage Between Power Tilt/Telescopic Steering Control Unit Connector A (16P) Terminals 2 And 16
    G08077082Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage when the tilt switch is operated? 

    YES  -Replace the steering column assembly (see STEERING COLUMN REMOVAL AND INSTALLATION ).

    NO  -Replace the power tilt/telescopic steering control unit (see POWER TILT/TELESCOPIC STEERING CONTROL UNIT INPUT TEST/REPLACEMENT  ).

  24. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  25. Check the No. 7 (20 A) fuse in the auxiliary under-hood fuse/relay box.

    Is the fuse OK? 

    YES  -Go to step 26.

    NO  -Replace the fuse. If the fuse blows again, repair a short to ground on the No. 7 (20 A) fuse circuit.

  26. Measure the voltage between body ground and power tilt/telescopic steering control unit connector B (8P) terminal No. 3.
    Fig 6: Measuring Voltage Between Body Ground And Power Tilt/Telescopic Steering Control Unit Connector B (8P) Terminal 3
    G08077083Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 27.

    NO  -Repair an open or high resistance in the wire between the driver's under-dash fuse/relay box and the power tilt/telescopic steering control unit.

  27. Measure the voltage between body ground and power tilt/telescopic steering control unit connector B (8P) terminal No. 1 when operating the tilt up-down switch.
    Fig 7: Measuring Voltage Between Body Ground And Power Tilt/Telescopic Steering Control Unit Connector B (8P) Terminal 1
    G08077084Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there 0.2 V or more? 

    YES  -Repair an open or high resistance in the wire between the power tilt/telescopic steering control unit and body ground (G403).

    NO  -Go to step 28.

  28. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  29. Disconnect power tilt/telescopic steering control unit connector B (8P).
  30. Disconnect the power tilt motor/position sensor 8P connector.
  31. Check for continuity between power tilt/telescopic steering control unit connector B (8P) terminals No. 7 and No. 8 and power tilt motor/position sensor 8P connector terminals No. 2 and No. 3 respectively.
    Fig 8: Checking Continuity Between Power Tilt/Telescopic Steering Control Unit Connector B (8P) And Power Tilt Motor/Position Sensor 8P Connector Terminals
    G08077085Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 32.

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

  32. Check for continuity between body ground and power tilt motor/position sensor 8P connector terminals No. 2 and No. 3 individually.
    Fig 9: Checking Continuity Between Body Ground And Power Tilt Motor/Position Sensor 8P Connector Terminals 2 And 3
    G08077086Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to ground in the wire(s).

    NO  -Go to step 33.

  33. Do the tilt motor test (see POWER TILT/TELESCOPIC STEERING MOTOR TEST  ).

    Is the motor OK? 

    YES  -Replace the power tilt/telescopic steering control unit (see POWER TILT/TELESCOPIC STEERING CONTROL UNIT INPUT TEST/REPLACEMENT  ).

    NO  -Replace the steering column assembly (see STEERING COLUMN REMOVAL AND INSTALLATION ).

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