DTC : B1826

DTC B1826  : Front height pulse error (no change in pulse for 1 second)

DTC (Power Seat Control Unit)

• NOTE:  If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Go to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks .
• If DTC B1825 and B1826 are both indicated, check for a blown No. C36 (20 A) fuse in the under-dash fuse/relay box. If the fuse blows again, check for a short to ground in the front up-down motor circuit.

1. Problem verification

   - 1. Clear the DTCs with the HDS.

   Clear DTCs

   - 2. Operate the power seat to its highest and then to its lowest position. (Two times)

   - 3. Check for DTCs with the HDS.

   DTC Description	DTC
   B1826 Front height pulse error (no change in pulse for 1 second)

   Is DTC B1826 indicated?

   DTC B1826 is indicated

   Go to step 2.

   DTC B1836 is also indicated

   Go to the DTC B1836 troubleshooting.

   DTC B1825, B1827, and/or B1828 are also indicated

   Go to step 6.

   NO 

   Intermittent failure, the system is OK at this time. Check for loose or poor connections.

2. Determine possible failure area (motor operation, motor sensor)

   - 1. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

   - 2. Operate the front up-down switch for 2 seconds, and check the front up-down motor operation.

   Does the front up-down motor run smoothly?

   YES 

   Go to step 3.

   NO 

   Go to step 8.

3. Open wire check (FHSE, SEG lines)

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connectors.

   Front up-down motor/position sensor 6P connector

   Power seat control unit connector A (20P)

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector A (20P): disconnected
   Test point 1	Front up-down motor/position sensor 6P connector No. 2
   Test point 2	Power seat control unit connector A (20P) No. 7

   Test point 1	Front up-down motor/position sensor 6P connector No. 6
   Test point 2	Power seat control unit connector A (20P) No. 19

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The FHSE, SEG wires are not open. Go to step 4.

   NO 

   Repair an open or high resistance in the wire.

4. Shorted wire check (FHSE line)

   - 1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector A (20P): disconnected
   Test point 1	Power seat control unit connector A (20P) No. 7
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short to ground in the wire.

   NO 

   The FHSE wire is not shorted. Go to step 5.

5. Front up-down position sensor check

   - 1. Reconnect the following connector.

   Power seat control unit connector A (20P)

   - 2. Turn the vehicle to the ON mode.

   - 3. Measure the voltage between test points 1(+) and 2(-).

   Test condition	Vehicle ON mode Front up-down motor/position sensor 6P connector: disconnected
   Test point 1	Front up-down motor/position sensor 6P connector No. 2 (+)
   Test point 2	Front up-down motor/position sensor 6P connector No. 6 (-)

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5 V?

   About 5 V

   Faulty front up-down motor/position sensor; replace the Front Seat Frame - Removal and Installation .

   No voltage

   Replace the Power Seat Control Unit - Removal and Installation .

   Battery voltage

   Repair a short to power in the wire (sensor line).

6. Open wire check (SVCC, SEG lines)

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connectors.

   Front up-down motor/position sensor 6P connector

   Power seat control unit connector A (20P)

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector A (20P): disconnected
   Test point 1	Front up-down motor/position sensor 6P connector No. 5
   Test point 2	Power seat control unit connector A (20P) No. 6

   Test point 1	Front up-down motor/position sensor 6P connector No. 6
   Test point 2	Power seat control unit connector A (20P) No. 19

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The SVCC and SEG wires are OK. Go to step 7.

   NO 

   Repair an open or high resistance in the wire.

7. Power seat control unit check

   - 1. Reconnect the following connector.

   Power seat control unit connector A (20P)

   - 2. Turn the vehicle to the ON mode.

   - 3. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode Front up-down motor/position sensor 6P connector: disconnected
   Test point 1	Power seat control unit connector A (20P) No. 6
   Test point 2	Power seat control unit connector A (20P) No. 19

   Is there battery voltage when the front up-down switch is operated?

   YES 

   Faulty front up-down motor/position sensor; replace the Front Seat Frame - Removal and Installation .

   NO 

   Replace the Power Seat Control Unit - Removal and Installation .

8. Fuse check

   - 1. Check the following fuse.

   Fuse	No. C36 (20 A)
   Location	Under-dash fuse/relay box

   Is the fuse OK?

   YES 

   Go to step 9.

   NO 

   Replace the fuse. If the fuse blows again, repair the short to ground in the No. C36 (20 A) fuse circuit.

9. Open wire check (+B DR P/SEAT(SLI) line)

   - 1. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   Test point 1	Power seat control unit connector B (12P) No. 6
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   The +B DR P/SEAT(SLI) wire is not open. Go to step 10.

   NO 

   Repair an open or high resistance in the wire.

10. Open wire check (GND line)

    - 1. Measure the voltage between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    Test point 1	Power seat control unit connector B (12P) No. 2
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there 0.2 V or more?

    YES 

    Repair an open or high resistance in the GND wire or poor ground (G601).

    NO 

    The GND wire is not open. Go to step 11.

11. Open wire check (FR HT UP, FR HT DN lines)

    - 1. Disconnect the following connectors.

    Front up-down motor/position sensor 6P connector

    Power seat control unit connector B (12P)

    - 2. Check for continuity between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector B (12P): disconnected
    Test point 1	Front up-down motor/position sensor 6P connector No. 3
    Test point 2	Power seat control unit connector B (12P) No. 10

    Test point 1	Front up-down motor/position sensor 6P connector No. 4
    Test point 2	Power seat control unit connector B (12P) No. 7

    Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The FR HT UP and FR HT DN wires are not open. Go to step 12.

    NO 

    Repair an open or high resistance in the wire.

12. Shorted wire check (FR HT UP, FR HT DN lines)

    - 1. Check for continuity between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector B (12P): disconnected
    Test point 1	Front up-down motor/position sensor 6P connector No. 3
    Test point 2	Body ground

    Test point 1	Front up-down motor/position sensor 6P connector No. 4
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair a short to ground in the wire.

    NO 

    The FR HT UP and FR HT DN wires are OK. Go to step 13.

13. Front up-down motor check

    - 1. Test the front up-down motor. Go to: Driver's Power Seat Motor

    Is the motor OK?

    YES 

    Replace the Power Seat Control Unit - Removal and Installation .

    NO 

    Faulty front up-down motor/position sensor; replace the Front Seat Frame - Removal and Installation .