Automatic Drive Positioner (DTC/Circuit Diagnosis)
- CHECK LIFTING SENSOR (FRONT) SIGNAL
- Turn ignition switch ON.
- Read the voltage signal between driver seat control unit harness connector B222 and ground with an oscilloscope.
(+)
(-)
Condition
Voltage signal
Driver seat control unit
Connector
Terminal
B222
30
Ground
Seat lifting
(front)
Operate
Other than above
0 V or 5 V
Is the inspection result normal?
YES
GO TO STEP 4
NO
GO TO STEP 2
- CHECK LIFTING SENSOR (FRONT) CIRCUIT
- Turn ignition switch OFF.
- Disconnect driver seat control unit and lifting motor LH (front).
- Check continuity between driver seat control unit harness connector B222 and lifting motor LH (front) harness connector B227.
Driver seat control unit
Lifting motor LH (front)
Continuity
Connector
Terminal
Connector
Terminal
B222
30
B227
1
Yes
- Check continuity between driver seat control unit harness connector B222 and ground.
Driver seat control unit
Ground
Continuity
Connector
Terminal
B222
30
No
Is the inspection result normal?
YES
GO TO STEP 3
NO
Repair or replace harness.
- CHECK LIFTING SENSOR (FRONT) POWER SUPPLY
- Connect driver seat control unit.
- Turn ignition switch ON.
- Check voltage between lifting motor LH (front) harness connector B227 and ground.
(+)
(-)
Voltage
(Approx.)
Lifting motor LH (front)
Connector
Terminal
B227
3
Ground
Battery voltage
Is the inspection result normal?
YES
GO TO STEP 5
NO
GO TO STEP 4
- CHECK LIFTING SENSOR (FRONT) POWER SUPPLY CIRCUIT
- Turn ignition switch OFF.
- Disconnect driver seat control unit.
- Check continuity between driver seat control unit harness connector B222 and lifting motor LH (front) harness connector B227.
Driver seat control unit
Lifting motor LH (front)
Continuity
Connector
Terminal
Connector
Terminal
B222
5
B227
3
Yes
- Check continuity between driver seat control unit harness connector B222 and ground.
Driver seat control unit
Ground
Continuity
Connector
Terminal
B222
5
No
Is the inspection result normal?
YES
Replace driver seat control unit. Refer to Removal and Installation .
NO
Repair or replace harness.
- CHECK LIFTING SENSOR (FRONT) GROUND
- Turn ignition switch OFF.
- Check continuity between lifting motor LH (front) harness connector B227 and ground.
Lifting motor LH (front)
Ground
Continuity
Connector
Terminal
B227
2
Yes
Is the inspection result normal?
YES
Replace lifting motor LH (front). Refer to Removal and Installation .
NO
Repair or replace harness.