Page 3937 of 4500
a. Disconnect the D25 ECU connector.
b. Measure the voltage and resistance of the wire harness side connector.
Standard:
TESTER CONNECTION AND SPECIFIED CONDITION
Fig. 20: Identifying D25 Driver Door ECU Connector Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
Tester connectionConditionSpecified condition
D25-4 (CPUB) - Body groundAlways10 to 14 V
D25-6 (BDR) - Body groundAlways10 to 14 V
D25-5 (SIG) - Body groundIgnition switch OFF --> ON0 V --> 10 to 14 V
D25-1 (GND) - Body groundAlwaysBelow 1 ohms
Page 3938 of 4500
CIRCUIT DESCRIPTION
The driver seat ECU receives signals from the power seat control switches and operates each power seat motor
according to its switch position.
WIRING DIAGRAM
Fig. 21: Power Seat Motor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Page 3939 of 4500

INSPECTION PROCEDURE
1.PERFORM ACTIVE TEST USING HAND-HELD TESTER
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON and push the hand-held tester (with CAN VIM) main switch ON.
c. Select the ACTIVE TEST on the hand-held tester to generate a control command, and then check
that the power seat operates.
Driver seat ECU:
DRIVER SEAT ECU - ACTIVE TEST
OK: The motor operates normally.
NG: Go to step 2
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
2.INSPECT POWER SEAT MOTOR (SEE INSPECTION
)
NG: REPLACE POWER SEAT MOTOR
OK: GO TO NEXT STEP
3.CHECK WIRE HARNESS (DRIVER SEAT ECU - POWER SEAT MOTOR AND BODY
GROUND)
a. Disconnect the D27 ECU, P27, P28, P29, P32 and P33 motor connectors.
b. Measure the resistance of the wire harness side connectors.
Standard:
ItemTest DetailsDiagnostic Note
RECLININGTest detail: reclining operation FRONT/REAR Vehicle
condition: stopped-
F VERTICALTest detail: front vertical operation UP/DOWN Vehicle
condition: stopped-
LIFTERTest detail: lifter operation UP/DOWN Vehicle condition:
stopped-
SLIDETest detail: sliding operation UP/DOWN Vehicle condition:
stopped-
HEADRESTTest detail: headrest operation UP/DOWN Vehicle condition:
stopped-
CUSHIONTest detail: cushion length operation FRONT/REAR Vehicle
condition: stopped-
Page 3940 of 4500
TESTER CONNECTION AND SPECIFIED CONDITION
Tester connectionSpecified condition
D27-10 (RCL-) - P32-1Below 1ohms
D27-13 (RCL+) - P32-2Below 1ohms
D27-4 (RRV-) - P29-1Below 1ohms
D27-9 (RRV+) - P29-2Below 1ohms
D27-1 (SLD-) - P33-1Below 1ohms
D27-8 (SLD+) - P33-2Below 1ohms
D27-11 (C-) - P27-2Below 1ohms
D27-7 (C+) - P27-1Below 1ohms
D27-2 (FPV-) - P28-2Below 1ohms
D27-5 (FPV+) - P28-1Below 1ohms
D27-6 (GND) - Body groundBelow 1ohms
Page 3941 of 4500
Page 3942 of 4500
Fig. 22: Identifying D27 Driver Seat ECU Connector Terminals And Power Seat Motor Connector
Terminals
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
NG: REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR
OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS
TABLE
CIRCUIT DESCRIPTION
The position sensor detects seat movement and sends pulse signals to the driver seat ECU for use with the
memory function.
The ECU records the number of pulses relative to a previously recorded seat position and uses this data to
return the seat to that position.
If a malfunction occurs in a position sensor and seat movement does not result in pulse signals being input into
the ECU, the memory function is deactivated.
WIRING DIAGRAM
Page 3943 of 4500
Fig. 23: Position Sensor Wiring Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
Page 3944 of 4500

INSPECTION PROCEDURE
1.READ VALUE OF HAND-HELD TESTER
a. Connect the hand-held tester (with CAN VIM) to the DLC3.
b. Turn the ignition switch ON and press the hand-held tester main switch ON.
c. Select the items below in the DATA LIST, and read the hand-held tester's screen.
d. Watch the hand-held tester screen while adjusting the seat with the power seat control switches.
Check that the position sensor value changes.
e. Watch the hand-held tester screen while adjusting the seat with the power seat control switches.
Check that the motor status changes from STANDBY to MOVING.
HINT:
When the seat is at an extreme position (for example, seatback position fully forward or sliding position
fully rearward) and the power seat control switch is held down, the motor status should read LOCK.
When the switch is released, the motor status should change to STANDBY.
Driver seat ECU:
Fig. 24: Driver Seat ECU
- Data List Chart
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
OK:
Position sensor values should vary within the minimum and maximum values shown in the chart
above.
For the tester's motor status item, the display should change between STANDBY, MOVING and