Toyota Tundra Service Manual: One or more Power Seat Motors do not Operate

Toyota Tundra Service Manual / Vehicle Interior / Seat / Front Power Seat Control System(w/ Memory) / One or more Power Seat Motors do not Operate

DESCRIPTION

When a signal is input into the position control ECU and switch assembly, the ECU manages the signals received from the power seat switches, and operates each motors. If the position control ECU and switch assembly receives more than 2 motor operation signals, the motor is stopped. Manual operation is restarted after the position control ECU and switch assembly receives 1 signal only.

WIRING DIAGRAM

PROCEDURE

1.	CHECK FRONT POWER SEAT OPERATION

(a) Check which power seat functions are malfunctioning.

Result

Result	Proceed to
One or more power seat functions do not operate	A
All power seat functions do not operate	B

GO to OTHER FLOW CHART (Front Power Seat does not Operate with Front Power Seat Switch)

2.	CHECK FRONT POWER SEAT OPERATION

(a) Check that each function of the power seat operates normally by using the power seat switches (See page ).

Result

Result	Proceed to
Slide, front vertical and lifter functions do not operate	A
Reclining functions do not operate	B
Lumbar support adjustment function does not operate	C
Leg support function does not operate	D

GO TO STEP 7

GO TO STEP 11

GO TO STEP 15

3.	READ VALUE USING TECHSTREAM (SLIDE, LIFTER, FRONT VERTICAL)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Driver Seat / Data List.

(e) Read the Data List according to the display on the Techstream.

Driver Seat

Tester Display	Measurement item/Range	Normal Condition	Diagnostic Note
Front Vertical Down	Front vertical switch signal (Downward) / ON or OFF	ON: Front vertical switch (Downward) on OFF: Front vertical switch (Downward) off	-
Front Vertical Up	Front vertical switch signal (Upward) / ON or OFF	ON: Front vertical switch (Upward) on OFF: Front vertical switch (Upward) off	-
Lifter Switch Down	Lifter switch signal (Downward) / ON or OFF	ON: Lifter switch (Downward) on OFF: Lifter switch (Downward) off	-
Lifter Switch Up	Lifter switch signal (Upward) / ON or OFF	ON: Lifter switch (Upward) on OFF: Lifter switch (Upward) off	-
Slide Rear	Sliding switch signal (Rearward) / ON or OFF	ON: Sliding switch (Rearward) on OFF: Sliding switch (Rearward) off	-
Slide Front	Sliding switch signal (Forward) / ON or OFF	ON: Sliding switch (Forward) on OFF: Sliding switch (Forward) off	-

OK:

ON or OFF is displayed on the Techstream according to the table above.

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

4.	INSPECT FRONT SEAT CUSHION FRAME SUB-ASSEMBLY LH (SLIDE, LIFTER, VERTICAL MOTOR)

(a) Check the operation of the slide motor.

(1) Remove the front seat cushion frame sub-assembly LH (slide motor) (See page ).

(2) Inspect the front seat cushion frame sub-assembly LH (slide motor) (See page ).

(b) Check the operation of the lifter motor.

(1) Remove the front seat cushion frame sub-assembly LH (lifter motor) (See page ).

(2) Inspect the front seat cushion frame sub-assembly LH (lifter motor) (See page ).

(1) Remove the front seat cushion frame sub-assembly LH (vertical motor) (See page ).

(2) Inspect the front seat cushion frame sub-assembly LH (vertical motor) (See page ).

REPLACE FRONT SEAT CUSHION FRAME SUB-ASSEMBLY LH

5.	CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU AND SWITCH ASSEMBLY - FRONT SEAT CUSHION FRAME SUB-ASSEMBLY LH)

(a) Disconnect the Z9 and Z10 position control ECU and switch assembly connectors.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Z10-5 (SSRS) - Z3-5	Always	Below 1 Ω
Z9-3 (SLD+) - Z3-4	Always	Below 1 Ω
Z9-4 (SLD-) - Z3-3	Always	Below 1 Ω
Z10-1 (SGND) - Z3-6	Always	Below 1 Ω
Z10-3 (SSFV) - Z14-2	Always	Below 1 Ω
Z9-8 (FRV+) - Z5-2	Always	Below 1 Ω
Z9-5 (FRV-) - Z5-1	Always	Below 1 Ω
Z10-1 (SGND) - Z14-1	Always	Below 1 Ω
Z10-4 (SSRL) - Z4-4	Always	Below 1 Ω
Z9-10 (LFT+) - Z4-1	Always	Below 1 Ω
Z9-12 (LFT-) - Z4-2	Always	Below 1 Ω
Z10-1 (SGND) - Z4-3	Always	Below 1 Ω
Z10-5 (SSRS) or Z3-5 - Body ground	Always	10 kΩ or higher
Z9-3 (SLD+) or Z3-4 - Body ground	Always	10 kΩ or higher
Z9-4 (SLD-) or Z3-3 - Body ground	Always	10 kΩ or higher
Z10-1 (SGND) or Z3-6 - Body ground	Always	10 kΩ or higher
Z10-1 (SGND) or Z14-1 - Body ground	Always	10 kΩ or higher
Z10-1 (SGND) or Z4-3 - Body ground	Always	10 kΩ or higher
Z10-3 (SSFV) or Z14-2 - Body ground	Always	10 kΩ or higher
Z9-8 (FRV+) or Z5-2 - Body ground	Always	10 kΩ or higher
Z9-5 (FRV-) or Z5-1 - Body ground	Always	10 kΩ or higher
Z10-4 (SSRL) or Z4-4 - Body ground	Always	10 kΩ or higher
Z9-10 (LFT+) or Z4-1 - Body ground	Always	10 kΩ or higher
Z9-12 (LFT-) or Z4-2 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK POSITION CONTROL ECU AND SWITCH ASSEMBLY

(a) Temporarily replace the position control ECU and switch assembly with a new or normally functioning one (See page ).

(b) Check the front power seat control system (See page ).

OK:

Power seat operates normally.

END (POSITION CONTROL ECU AND SWITCH ASSEMBLY WAS DEFECTIVE)

REPLACE FRONT SEAT CUSHION FRAME SUB-ASSEMBLY LH

7.	READ VALUE USING TECHSTREAM (RECLINING)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Driver Seat / Data List.

(e) Read the Data List according to the display on the Techstream.

Driver Seat

Tester Display

Measurement item/Range

Normal Condition

Diagnostic Note

Reclining Rear

Reclining switch signal (Rearward) / ON or OFF

ON: Reclining switch (Rearward) on

OFF: Reclining switch (Rearward) off

Reclining Front

Reclining switch signal (Forward) / ON or OFF

ON: Reclining switch (Forward) on

OFF: Reclining switch (Forward) off

OK:

ON or OFF is displayed on the Techstream according to the table above.

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

8.	INSPECT FRONT SEATBACK FRAME SUB-ASSEMBLY LH (RECLINING MOTOR)

(a) Check the operation of the reclining motor.

(1) Remove the front seatback frame sub-assembly LH (reclining motor) (See page ).

(2) Inspect the front seatback frame sub-assembly LH (reclining motor) (See page ).

REPLACE FRONT SEATBACK FRAME SUB-ASSEMBLY LH

9.	CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU AND SWITCH ASSEMBLY - FRONT SEATBACK FRAME SUB-ASSEMBLY LH)

(a) Disconnect the Z9 and Z10 position control ECU and switch assembly connectors.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Z10-11 (SSRR) - Z6-4	Always	Below 1 Ω
Z9-9 (RCL+) - Z6-2	Always	Below 1 Ω
Z9-11 (RCL-) - Z6-1	Always	Below 1 Ω
Z10-1 (SGND) - Z6-3	Always	Below 1 Ω
Z10-11 (SSRR) or Z6-4 - Body ground	Always	10 kΩ or higher
Z9-9 (RCL+) or Z6-2 - Body ground	Always	10 kΩ or higher
Z9-11 (RCL-) or Z6-1 - Body ground	Always	10 kΩ or higher
Z10-1 (SGND) or Z6-3 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

10.	CHECK POSITION CONTROL ECU AND SWITCH ASSEMBLY

(a) Temporarily replace the position control ECU and switch assembly with a new or normally functioning one (See page ).

(b) Check the front power seat control system (See page ).

OK:

Power seat operates normally

END (POSITION CONTROL ECU AND SWITCH ASSEMBLY WAS DEFECTIVE)

REPLACE FRONT SEATBACK FRAME SUB-ASSEMBLY LH

11.	INSPECT LUMBAR SUPPORT ADJUSTER ASSEMBLY LH (LUMBAR MOTOR)

(a) Check the operation of the lumbar motor.

(1) Remove the lumbar support adjuster assembly LH (lumbar motor) (See page ).

(2) Inspect the lumbar support adjuster assembly LH (lumbar motor) (See page ).

REPLACE LUMBAR SUPPORT ADJUSTER ASSEMBLY LH (LUMBAR MOTOR)

12.	INSPECT FRONT POWER SEAT SWITCH LH (LUMBAR SUPPORT CONTROL)

(a) Check the operation of the lumbar support control.

(1) Remove the front power seat switch LH (lumbar support control) (See page ).

(2) Inspect the front power seat switch LH (lumbar support control) (See page ).

REPLACE FRONT POWER SEAT SWITCH LH

13.	CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU AND SWITCH ASSEMBLY - FRONT POWER SEAT SWITCH LH)

(a) Disconnect the Z9 position control ECU and switch assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Z9-6 (+B2) - Z2-5 (B)	Always	Below 1 Ω
Z9-1 (GND2) - Z2-2 (E)	Always	Below 1 Ω
Z9-6 (+B2) or Z2-5 (B) - Body ground	Always	10 kΩ or higher
Z9-1 (GND2) or Z2-2 (E) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	CHECK HARNESS AND CONNECTOR (LUMBAR SUPPORT ADJUSTER ASSEMBLY LH - FRONT POWER SEAT SWITCH LH)

(a) Disconnect the Z7 lumbar support adjuster assembly LH (lumbar motor) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Z2-1 (R) - Z7-1	Always	Below 1 Ω
Z2-3 (H) - Z7-2	Always	Below 1 Ω
Z2-1 (R) or Z7-1 - Body ground	Always	10 kΩ or higher
Z2-3 (H) or Z7-2 - Body ground	Always	10 kΩ or higher

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

15.	INSPECT FRONT SEAT CUSHION FRAME SUB-ASSEMBLY LH (LEG MOTOR)

(a) Check the operation of the leg motor.

(1) Remove the front seat cushion frame sub-assembly LH (leg motor) (See page ).

(2) Inspect the front seat cushion frame sub-assembly LH (leg motor) )(See page ).

REPLACE FRONT SEAT CUSHION FRAME SUB-ASSEMBLY LH

16.	INSPECT FRONT POWER SEAT SWITCH LH (SEAT CUSHION CONTROL)

(a) Check the operation of the seat cushion control.

(1) Remove the front power seat switch LH (seat cushion control) (See page ).

(2) Inspect the front power seat switch LH (seat cushion control) (See page ).

REPLACE FRONT POWER SEAT SWITCH LH

17.	CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU AND SWITCH ASSEMBLY - FRONT POWER SEAT SWITCH LH)

(a) Disconnect the Z9 position control ECU and switch assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Z9-7 (+B1) - Z15-2	Always	Below 1 Ω
Z9-2 (GND1) - Z15-1	Always	Below 1 Ω
Z9-2 (GND1) - Z15-4	Always	Below 1 Ω
Z9-7 (+B1) or Z15-2 - Body ground	Always	10 kΩ or higher
Z9-2 (GND1) or Z15-1 - Body ground	Always	Below 1 Ω
Z9-2 (GND1) or Z15-4 - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

18.	CHECK HARNESS AND CONNECTOR (FRONT SEAT CUSHION FRAME SUB-ASSEMBLY LH - FRONT POWER SEAT SWITCH LH)

(a) Disconnect the Z8 front seat cushion frame sub-assembly LH (leg motor) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Z15-5 - Z8-2	Always	Below 1 Ω
Z15-3 - Z8-1	Always	Below 1 Ω
Z15-5 or Z8-2 - Body ground	Always	10 kΩ or higher
Z15-3 or Z8-1 - Body ground	Always	10 kΩ or higher

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

Initialization

Operation Check

See More:

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