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DTC B1826: Front Up-down Motor Pulse 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 ).
  1. Clear the DTC with the HDS.
  2. Turn the ignition switch OFF, and then back ON (II).
  3. Move the front of the power seat up and down with the power seat adjustment switch for more than 2 seconds in each direction.

    Does the motor run continuously for more than 2 seconds? 

    1. YES  - Intermittent failure, the system is OK at this time. Check for a poor connection at the sensor and at the power seat control unit connector A (20P).
    2. NO  - Go to step  4.
  4. Move the power seat up and down with the power seat adjustment switch again.

    Does the motor run for about 1 second? 

    1. YES  - Go to step  5.
    2. NO  - Go to step  16.
  5. Turn the ignition switch OFF.
  6. Remove the driver's power seat (see FRONT SEAT REMOVAL/INSTALLATION ).
  7. Disconnect the power seat control unit connector A (20P), slide position sensor connector (3P), and front up-down motor/position sensor connector (5P).
  8. Check for continuity between the front up-down motor/position sensor connector (5P) No. 5 terminal and power seat control unit connector A (20P) No. 12 terminal.
    Fig 1: Checking Continuity Between Front Up-Down Motor/Position Sensor Connector No. 5 Terminal & Power Seat Control Unit Connector No. 12
    G03662329Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  9.
    2. NO  - Repair open in the GRN/BLK wire.
  9. Check for continuity between the front up-down motor/position sensor connector (5P) No. 5 terminal and body ground.
    Fig 2: Checking Continuity Between Front Up-Down Motor/Position Sensor Connector (5P) No. 5 Terminal & Body Ground
    G03662330Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Repair a short in the GRN/BLK wire.
    2. NO  - Go to step  10.
  10. Check for continuity between the front up-down motor/position sensor connector (5P) No. 3 terminal and power seat control unit connector A (20P) No. 1 terminal.
    Fig 3: Checking Continuity Between Front Up-Down Motor/Position Sensor Connector (5P) No. 3 & Power Seat Control Unit Connector A (20P) No. 1 Terminal
    G03662331Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  11.
    2. NO  - Repair open in the BRN wire.
  11. Check for continuity between the front up-down motor/position sensor connector (5P) No. 3 terminal and body ground.
    Fig 4: Checking Continuity Between Front Up-Down Motor/Position Sensor Connector (5P) No. 3 Terminal & Body Ground
    G03662332Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Repair a short in the BRN wire.
    2. NO  - Go to step  12.
  12. Check for continuity between the front up-down motor/position sensor connector (5P) No. 4 terminal and power seat control unit connector A (20P) No. 11 terminal.
    Fig 5: Checking Continuity Between Front Up-Down Motor/Position Sensor Connector (5P) No. 4 Terminal & Power Seat Control Unit Connector A (20P) No. 11
    G03662333Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  13.
    2. NO  - Repair open in the WHT/BLK wire.
  13. Reconnect the power seat control unit connector A (20P).
  14. Turn the ignition switch ON (II).
  15. Measure voltage between the power seat control unit connector A (20P) No. 1 and No. 11 terminals.
    Fig 6: Measuring Voltage Between Power Seat Control Unit Connector A (20P) No. 1 & No. 11 Terminals
    G03662334Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 5 V? 

    1. YES  - Replace the front up-down motor/position sensor.
    2. NO  - Replace the power seat control unit.
  16. Turn the ignition switch OFF.
  17. Check the No. 14 (20 A) fuse in the under-dash fuse/relay box.

    Is the fuse OK? 

    1. YES  - Go to step  18.
    2. NO  - Replace the fuse and retest. If the fuse blows again, repair the short in the wire.
  18. Disconnect the power seat control unit connector B (8P).
  19. Measure the voltage between the No. 3 terminal of power seat control unit connector B (8P) and body ground.
    Fig 7: Measuring Voltage Between No. 3 Terminal Of Power Seat Control Unit Connector B (8P) & Body Ground
    G03662335Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  - Go to step  20.
    2. NO  - Repair an open in the wire between the under-dash fuse/relay box and the power seat control unit.
  20. Check for continuity between the No. 7 terminal of power seat control unit connector B (8P) and body ground.
    Fig 8: Checking Continuity Between No. 7 Terminal Of Power Seat Control Unit Connector B (8P) & Body Ground
    G03662336Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  21.
    2. NO  - Repair an open in the wire between the power seat control unit and G503, G601. If the wire is OK, repair G503, G601.
  21. Disconnect the front up-down motor connector (5P).
  22. Check for continuity between the following terminals of the power seat control unit connector B (8P) and the front up-down motor connector (5P).
    TERMINALS SPECIFICATION

    8P: 5P:
    No. 4 No. 1
    No. 8 No. 2
    Fig 9: Checking Continuity Between Terminals Of Power Seat Control Unit Connector B (8P) & Front Up-Down Motor Connector (5P)
    G03662337Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  23.
    2. NO  - Repair an open in the wire between the power seat control unit connector B (8P) and the front up-down motor connector (5P).
  23. Remove the driver's power seat (see FRONT SEAT REMOVAL/INSTALLATION ).
  24. Test the front up-down motor (see DRIVER'S POWER SEAT MOTOR TEST ).

    Is the front up-down motor OK? 

    1. YES  - Repair an open or a short in the front up-down motor/position sensor wires.
    2. NO  - Replace the front up-down motor/position sensor.