DTC B1826: Power Seat Front Up-down Motor Pulse Error
- 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 ).
- DTC B1826 is stored when the front up-down switch is operated more than 1 second after the seat moves to the most up or most down position, even when the system is OK.
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0), and then back to ON (II).
- Operate the power seat adjustment switch in each direction for at least 1 second each.
- Check for the DTCs with the HDS.
Is DTC B1826 indicated?
YES -Go to step 5.
NO -Intermittent failure, the front up-down position sensor is OK at this time. Check for loose or poor connections at the power seat control unit connectors.
- Check for DTCs with the HDS.
Is DTC B1836 also indicated?
YES -Troubleshoot DTC B1836 first (see DTC B1836: POWER SEAT POSITION SENSOR CIRCUIT SHORT ).
NO -Go to step 6.
- Check for DTCs with the HDS.
Are DTCs B1825, B1827 and/or B1828 also indicated?
YES -Go to step 18.
NO -Go to step 7.
- Clear the DTCs with the HDS.
- Turn the ignition switch to LOCK (0), and then back to ON (II).
- Operate the front up-down switch for at least 2 seconds, and check the front up-down motor operation.
Does the front up-down motor run smoothly?
YES -Go to step 10.
NO -Go to step 25.
- Turn the ignition switch to LOCK (0).
- Disconnect power seat control unit connector A (40P).
- Disconnect the front up-down motor/position sensor 5P connector.
- Check for continuity between power seat control unit connector A (40P) terminals No. 12, No. 15, and No. 29 and front up-down motor/position sensor 5P connector terminals No. 3, No. 4, and No. 5 respectively.Fig 1: Checking Continuity Between Power Seat Control Unit Connector A (40P) Terminals No. 12, No. 15, And No. 29
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 14.
NO -Repair open in the wire.
- Check for continuity between power seat control unit connector A (40P) terminal No. 12 and body ground.Fig 2: Checking Continuity Between Power Seat Control Unit Connector A (40P) Terminal No. 12 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair short to ground in the wire.
NO -Go to step 15.
- Reconnect power seat control unit connector A (40P).
- Turn the ignition switch to ON (II).
- Measure the voltage between front up-down motor/position sensor 5P connector terminals No. and No. 5.Fig 3: Measuring Voltage Between Front Up-Down Motor/Position Sensor 5P Connector Terminals No. And No. 5
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there about 5 V?
YES -Replace the front up-down motor/position sensor.
NO -If there is no voltage, replace the power seat control unit. If there is battery voltage, repair short in the wire (sensor line).
- Turn the ignition switch to LOCK (0).
- Disconnect power seat control unit connector A (40P>.
- Disconnect the front up-down motor/position sensor 5P connector.
- Check for continuity between power seat control unit connector A (40P) terminals No. 15 and No. 29 and front up-down motor/position sensor 5P connector terminals No. 3 and No. 4 respectively.Fig 4: Checking Continuity Between Power Seat Control Unit Connector A (40P) Terminals No. 15 And No. 29
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 22.
NO -Repair open in the wire.
- Reconnect power seat control unit connector A (40P).
- Turn the ignition switch to ON (II).
- Measure the voltage between power seat control unit connector A (40P) terminals No. 15 and No. 29.Fig 5: Measuring Voltage Between Power Seat Control Unit Connector A (40P) Terminals No. 15 And No. 29
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage when the front up-down switch is operated?
YES -Replace the front up-down motor/position sensor, and recheck for DTCs.
NO -Replace the power seat control unit.
- Turn the ignition switch to LOCK (0).
- Disconnect power seat control unit connector B (18P).
- Disconnect the front up-down motor/position sensor 5P connector.
- Check for continuity between power seat control unit connector B (18P) terminals No. 6 and No. 16 and front up-down motor/position sensor 5P connector terminals No. 1 and No. 2 respectively.Fig 6: Checking Continuity Between Power Seat Control Unit Connector B (18P) Terminals No. 6 And No. 16
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 29.
NO -Repair open in the wire.
- Check for continuity between front up-down motor/ position sensor 5P connector terminals No. 1 and No. 2 and body ground.Fig 7: Checking Continuity Between Front Up-Down Motor/ Position Sensor 5P Connector Terminals No. 1 And No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair short to ground in the wire.
NO -Go to step 30.
- Do the front up-down motor test (see
DRIVER'S POWER SEAT MOTOR TEST ).
Is the motor OK?
YES -Replace the power seat control unit.
NO -Replace the front-up-down motor/position sensor.