DTC B1827: Power Seat Rear 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 ).

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 for several seconds in each direction.
NOTE: DTC B1827 is stored when the rear up-down switch is operated more than 1 second after the seat moves to the most up or down position, even when the system is OK.
Check for the DTCs with the HDS.
Is DTC B1827 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections.
Clear the DTCs with the HDS.
Is DTC B1836 also indicated?

YES -Go to the DTC B1836 TROUBLESHOOTING .

NO -Go to step 6.
Clear the DTCs with the HDS.
Are DTCs B1825, B1826, and/or B1828 also indicated?

YES -Go to step 17.

NO -Go to step 7.
Turn the ignition switch to LOCK (0) and then back to ON (II).
Operate the rear up-down switch for 2 seconds, and check the rear up-down motor operation.
Does the rear up-down motor run smoothly?

YES -Go to step 9.

NO -Go to step 26.
Turn the ignition switch to LOCK (0).
Disconnect power seat control unit connector A (40P).
Disconnect the rear up-down motor/position sensor 5P connector.
Check for continuity between power seat control unit connector A (40P) terminals No. 13 and No. 29 and rear up-down motor/position sensor 5P connector terminals No. 5 and No. 4 respectively.

Fig 1: Checking Continuity Between Power Seat Control Unit Connector A (40P) Terminals No. 13 And No. 29

Is there continuity?

YES -Go to step 13.

NO -Repair an open in the wire.
Check for continuity between body ground and power seat control unit connector A (40P) terminal No. 13.

Fig 2: Checking Continuity Between Body Ground And Power Seat Control Unit Connector A (40P) Terminal No. 13

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to step 14.
Reconnect power seat control unit connector A (40P).
Turn the ignition switch to ON (II).
Measure the voltage between rear up-down motor/position sensor 5P connector terminals No. 5 (+) and No. 4(-).

Fig 3: Measuring Voltage Between Rear Up-Down Motor/Position Sensor 5P Connector Terminals 5 And 4

Is there about 5 V?

YES -Replace the rear up-down motor/position sensor (see REAR UP-DOWN MOTOR - DRIVER'S SEAT ).

NO -If there is no voltage, replace the power seat control unit (see POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT ). If there is battery voltage, repair a short in the wire (sensor line).
Turn the ignition switch to LOCK (0).
Disconnect power seat control unit connector A (40P).
Disconnect the rear 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 rear 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 15 And 29

Is there continuity?

YES -Go to step 21.

NO -Repair an open in the wire.
Disconnect the 5P connector from the slide motor/position sensor, front up-down motor/position sensor, and recline motor/position sensor.
Check for continuity between body ground and rear up-down motor/position sensor 5P connector terminal No. 3.

Fig 5: Checking Continuity Between Body Ground And Rear Up-Down Motor/Position Sensor 5P Connector Terminal 3

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to step 23.
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 6: Measuring Voltage Between Power Seat Control Unit Connector A (40P) Terminals No. 15 And No. 29

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

YES -Replace the rear up-down motor/position sensor (see REAR UP-DOWN MOTOR - DRIVER'S SEAT ).

NO -Replace the power seat control unit (see POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT ).
Turn the ignition switch to LOCK (0).
Disconnect power seat control unit connector B (18P).
Disconnect the rear up-down motor/position sensor 5P connector.
Check for continuity between power seat control unit connector B (18P) terminals No. 2 and No. 10 and rear up-down motor/position sensor 5P connector terminals No. 2 and No. 1 respectively.

Fig 7: Checking Continuity Between Power Seat Control Unit Connector B (18P) Terminals No. 2 And No. 10

Is there continuity?

YES -Go to step 30.

NO -Repair an open in the wire.
Check for continuity between body ground and rear up-down motor/position sensor 5P connector terminals No. 1 and No. 2 individually.

Fig 8: Checking Continuity Between Body Ground And Rear Up-Down Motor/Position Sensor 5P Connector Terminals 1 And 2

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to step 31.
Test the rear up-down motor (see DRIVER'S POWER SEAT MOTOR TEST ).
Is the motor OK?

YES -Replace the power seat control unit (see POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT ).

NO -Replace the rear up-down motor/position sensor (see REAR UP-DOWN MOTOR - DRIVER'S SEAT ).