Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJWC
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: SEAT: REAR POWER SEAT CONTROL SYSTEM: Reclining Motor Circuit; 2016 - 2020 MY Sienna [12/2015 -        ]

Reclining Motor Circuit

DESCRIPTION

The fold seat control ECU receives a switch operation signal from the rear power seat switch and the fold seat switch, and activates the reclining motor. At this time, the Hall IC (seatback position sensor) detects the actuation of the seatback and sends a seatback actuation signal to the fold seat control ECU. The fold seat control ECU uses signals from the Hall IC (seatback position sensor) to detect if an object is caught or if any other abnormal condition has occurred.

WIRING DIAGRAM

PROCEDURE

1.

CHECK FOLD SEAT CONTROL ECU

(a) Remove the fold seat control ECU with its connectors still connected (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SEAT: POWER SEAT CONTROL ECU(for Rear No. 2 Seat): REMOVAL ).

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

LH Side

Tester Connection

Condition

Specified Condition

b2-22 (SRCL) - b2-36 (SG2)

Motor is operating

Pulse generation

b2-25 (SV2) - b2-36 (SG2)

Back door open

9 to 14 V

b3-2 (RCL+) - b3-6 (RCL-)

Back door open

Lock switch unlock

Rear power seat switch on (Forward)

11 to 14 V

b3-6 (RCL-) - b3-2 (RCL+)

Back door open

Lock switch unlock

Rear power seat switch on (Backward)

11 to 14 V

RH Side

Tester Connection

Condition

Specified Condition

a2-22 (SRCL) - a2-36 (SG2)

Motor is operating

Pulse generation

a2-25 (SV2) - a2-36 (SG2)

Back door open

9 to 14 V

a3-2 (RCL+) - a3-6 (RCL-)

Back door open

Lock switch unlock

Rear power seat switch on (Forward)

11 to 14 V

a3-6 (RCL-) - a3-2 (RCL+)

Back door open

Lock switch unlock

Rear power seat switch on (Backward)

11 to 14 V

Text in Illustration

*a

Component with harness connected

(Fold Seat Control ECU)

*b

LH Side

*c

RH Side

(c) Reinstall the fold seat control ECU.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

(See page 2016 MY Sienna [12/2015 - 08/2016]; SEAT: REAR POWER SEAT CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE 2017 - 2020 MY Sienna [08/2016 -        ]; SEAT: REAR POWER SEAT CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE )

NG

2.

CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU - RECLINING MOTOR)

(a) Disconnect the b2 and b3 or a2 and a3 fold seat control ECU connectors.

(b) Disconnect the b4 and b5 or a4 and a5 reclining motor connectors.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

LH Side

Tester Connection

Condition

Specified Condition

b2-22 (SRCL) - b4-1 (HLS)

Always

Below 1 Ω

b2-22 (SRCL) - Body ground

Always

10 kΩ or higher

b2-25 (SV2) - b4-3 (HLV)

Always

Below 1 Ω

b2-25 (SV2) - Body ground

Always

10 kΩ or higher

b2-36 (SG2) - b4-2 (HLG)

Always

Below 1 Ω

b2-36 (SG2) - Body ground

Always

10 kΩ or higher

b3-2 (RCL+) - b5-1 (FWD)

Always

Below 1 Ω

b3-2 (RCL+) - Body ground

Always

10 kΩ or higher

b3-6 (RCL-) - b5-2 (BACK)

Always

Below 1 Ω

b3-6 (RCL-) - Body ground

Always

10 kΩ or higher

RH Side

Tester Connection

Condition

Specified Condition

a2-22 (SRCL) - a4-1 (HLS)

Always

Below 1 Ω

a2-22 (SRCL) - Body ground

Always

10 kΩ or higher

a2-25 (SV2) - a4-3 (HLV)

Always

Below 1 Ω

a2-25 (SV2) - Body ground

Always

10 kΩ or higher

a2-36 (SG2) - a4-2 (HLG)

Always

Below 1 Ω

a2-36 (SG2) - Body ground

Always

10 kΩ or higher

a3-2 (RCL+) - a5-1 (FWD)

Always

Below 1 Ω

a3-2 (RCL+) - Body ground

Always

10 kΩ or higher

a3-6 (RCL-) - a5-2 (BACK)

Always

Below 1 Ω

a3-6 (RCL-) - Body ground

Always

10 kΩ or higher

(d) Reconnect the reclining motor connectors.

(e) Reconnect the fold seat control ECU connectors.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

INSPECT NO. 2 SEATBACK FRAME SUB-ASSEMBLY (RECLINING MOTOR)

(a) Remove the No. 2 seatback frame sub-assembly (reclining motor) (See page 2016 - 2018 MY Sienna [12/2015 - 08/2018]; SEAT: REAR NO. 2 SEAT ASSEMBLY(for Power Seat Type LH Side): DISASSEMBLY 2019 - 2020 MY Sienna [08/2018 -        ]; SEAT: REAR NO. 2 SEAT ASSEMBLY(for Power Seat Type LH Side): DISASSEMBLY ).

(b) Check the operation of the reclining motor.

(1) Apply battery voltage to the reclining motor and check the operation of the reclining motor.

OK:

LH Side

Measurement Condition

Specified Condition

Battery positive (+) → Terminal 1

Battery negative (-) → Terminal 2

Forward

Battery positive (+) → Terminal 2

Battery negative (-) → Terminal 1

Backward

RH Side

Measurement Condition

Specified Condition

Battery positive (+) → Terminal 1

Battery negative (-) → Terminal 2

Forward

Battery positive (+) → Terminal 2

Battery negative (-) → Terminal 1

Backward

Text in Illustration

*a

Component without harness connected

(No. 2 Seatback Frame Sub-assembly (Reclining Motor))

(c) Reinstall the No. 2 seatback frame sub-assembly (reclining motor).

OK

REPLACE FOLD SEAT CONTROL ECU

NG

REPLACE NO. 2 SEATBACK FRAME SUB-ASSEMBLY

(See page 2016 - 2018 MY Sienna [12/2015 - 08/2018]; SEAT: REAR NO. 2 SEAT ASSEMBLY(for Power Seat Type LH Side): DISASSEMBLY 2019 - 2020 MY Sienna [08/2018 -        ]; SEAT: REAR NO. 2 SEAT ASSEMBLY(for Power Seat Type LH Side): DISASSEMBLY )