DTC Troubleshooting: B1826

DTC B1826: Front Height Pulse Error(no change in pulse for 1 second)

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

NOTE:

	If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A.
	If DTC B1825 and B1826 are both indicated, check for a blown No. B36 (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.

Problem verification:

Problem verification

?1.	Clear the DTCs with the HDS.

?2.	Press the engine start/stop button at least 20 times, then wait for at least 20 seconds.

?3.	Operate the power seat adjustment switch for several seconds in each direction. NOTE: 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 down position, even when the system is OK.

?4.

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.?

Determine possible failure area (motor operation, motor sensor):

Determine possible failure area (motor operation, motor sensor)

?1.	Press the engine start/stop button to select the OFF 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.

Open wire check (FHSE, SEG lines):

Open wire check (FHSE, SEG lines)

?1.	Press the engine start/stop button to select the OFF mode.

?2.

Disconnect the following connectors.

Front up-down motor/position sensor 6P connector

Power seat control unit connector B (20P)

?3.

Check for continuity between test points 1 and 2 respectively.

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

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

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.?

Shorted wire check (FHSE line):

Shorted wire check (FHSE line)

?1.

Check for continuity between test points 1 and 2.

Test condition	OFF mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector B (20P): disconnected
Test circuit	FHSE
Test point 1	Power seat control unit connector B (20P) No. 7 (PNK)
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.

Front up-down position sensor check:

Front up-down position sensor check

?1.	Reconnect power seat control unit connector B (20P).

?2.	Press the engine start/stop button to select the ON mode.

?3.

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

Test condition	ON mode Front up-down motor/position sensor 6P connector: disconnected
Test circuit	FHSE, SEG
Test point 1	Front up-down motor/position sensor 6P connector No. 2 (PNK) (+)
Test point 2	Front up-down motor/position sensor 6P connector No. 6 (WHT) (-)

Is there about 5 V?


	About 5 V

Faulty front up-down motor/position sensor; replace the seat frame assembly.?


	No voltage

Replace the power seat control unit.?


	Battery voltage

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

Open wire check (SVCC, SEG lines):

Open wire check (SVCC, SEG lines)

?1.	Press the engine start/stop button to select the OFF mode.

?2.

Disconnect the following connectors.

Front up-down motor/position sensor 6P connector

Power seat control unit connector B (20P)

?3.

Check for continuity between test points 1 and 2 respectively.

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

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

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.?

Power seat control unit check:

Power seat control unit check

?1.	Reconnect power seat control unit connector B (20P).

?2.	Press the engine start/stop button to select the ON mode.

?3.

Measure the voltage between test points 1 and 2.

Test condition	ON mode Front up-down motor/position sensor 6P connector: disconnected
Test circuit	SVCC, SEG
Test point 1	Power seat control unit connector B (20P) No. 6 (PUR)
Test point 2	Power seat control unit connector B (20P) No. 19 (WHT)

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


	YES

Faulty front up-down motor/position sensor; replace the seat frame assembly.?


	NO

Replace the power seat control unit.?

Fuse check:

Fuse check

?1.

Check the following fuse.

Fuse	No. B36 (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. B36 (20 A) fuse circuit.?

Open wire check (+B DR P/SEAT SLIDE/VMP1 line):

Open wire check (+B DR P/SEAT SLIDE/VMP1 line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	OFF mode
Test circuit	VMP1

2-door

Test point 1	Power seat control unit connector A (12P) No. 6 (PUR)
Test point 2	Body ground

4-door

Test point 1	Power seat control unit connector A (12P) No. 6 (LT BLU)
Test point 2	Body ground

Is there battery voltage?


	YES

The +B DR P/SEAT SLIDE/VMP1 wire is not open. Go to step 10.


	NO

Repair an open or high resistance in the wire.?

10.

Open wire check (PG 1 line):

Open wire check (PG 1 line)

?1.

Measure the voltage between test points 1 and 2.

Test condition	OFF mode
Test circuit	PG 1

2-door

Test point 1	Power seat control unit connector A (12P) No. 2 (PNK)
Test point 2	Body ground

4-door

Test point 1	Power seat control unit connector A (12P) No. 2 (GRY)
Test point 2	Body ground

Is there 0.2 V or more?


	YES

Repair an open or high resistance in the ground wire or poor ground (G651).?


	NO

The PG 1 wire is not open. Go to step 11.

11.

Open wire check (FR HEIGHT UP, FR HEIGHT DOWN lines):

Open wire check (FR HEIGHT UP, FR HEIGHT DOWN lines)

?1.

Disconnect the following connectors.

Front up-down motor/position sensor 6P connector

Power seat control unit connector A (12P)

?2.

Check for continuity between test points 1 and 2 respectively.

Test condition	OFF mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector A (12P): disconnected
Test circuit	FR HEIGHT UP
Test point 1	Front up-down motor/position sensor 6P connector No. 3 (ORN)
Test point 2	Power seat control unit connector A (12P) No. 10 (ORN)

2-door

Test circuit	FR HEIGHT DOWN
Test point 1	Front up-down motor/position sensor 6P connector No. 4 (YEL)
Test point 2	Power seat control unit connector A (12P) No. 7 (YEL)

4-door

Test circuit	FR HEIGHT DOWN
Test point 1	Front up-down motor/position sensor 6P connector No. 4 (BLU)
Test point 2	Power seat control unit connector A (12P) No. 7 (BLU)

Is there continuity?


	YES

The FR HEIGHT UP and FR HEIGHT DOWN wires are not open. Go to step 12.


	NO

Repair an open or high resistance in the wire.?

12.

Shorted wire check (FR HEIGHT MTR UP, FR HEIGHT MTR DOWN lines):

Shorted wire check (FR HEIGHT MTR UP, FR HEIGHT MTR DOWN lines)

?1.

Check for continuity between test points 1 and 2 individually.

Test condition	OFF mode Front up-down motor/position sensor 6P connector: disconnected Power seat control unit connector A (12P): disconnected
Test circuit	FR HEIGHT UP
Test point 1	Front up-down motor/position sensor 6P connector No. 3 (ORN)
Test point 2	Body ground

2-door

Test circuit	FR HEIGHT DOWN
Test point 1	Front up-down motor/position sensor 6P connector No. 4 (YEL)
Test point 2	Body ground

4-door

Test circuit	FR HEIGHT DOWN
Test point 1	Front up-down motor/position sensor 6P connector No. 4 (BLU)
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to ground in the wire.?


	NO

The FR HEIGHT UP and FR HEIGHT DOWN wires are OK. Go to step 13.

13.

Front up-down motor check:

Front up-down motor check

?1.	Test the front up-down motor.

Is the motor OK?


	YES

Replace the power seat control unit.?


	NO

Faulty front up-down motor/position sensor; replace the seat frame assembly.?