Toyota Tundra Service Manual: Power Seat does not Return to Memorized Position

Toyota Tundra Service Manual / Vehicle Interior / Seat / Front Power Seat Control System(w/ Memory) / Power Seat does not Return to Memorized Position

DESCRIPTION

When any of the M1or M2 switches is pressed, the front outer mirror control ECU assembly sends a switch signal to the main body ECU (multiplex network body ECU) via CAN communication. Then, the main body ECU (multiplex network body ECU) sends a recall request signal to the position control ECU and switch assembly. The position control ECU and switch assembly operates each motor to achieve each memorized position value.

WIRING DIAGRAM

PROCEDURE

1.

CHECK CAN COMMUNICATION SYSTEM

(a) Use the Techstream to check if the CAN communication system is functioning normally (See page ).

OK:

CAN communication DTC is not output.

NG

Go to CAN COMMUNICATION SYSTEM

OK

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 ).

OK:

Each function of the power seat operates normally by using the power seat switches.

NG

Go to PROBLEM SYMPTOMS TABLE

OK

3.

CHECK SEAT POSITION MEMORY FUNCTION

(a) Perform a memory operation and check that the buzzer sounds to indicate the completion of the memory operation (See page ).

NOTICE:

  • The seat position will not be recorded if the SET switch and 2 memory switches are pressed simultaneously.
  • If a memorizing operation has failed, release all switches. The seat memory function does not operate unless the switches are released.

OK:

Seat position memory function operates normally.

NG

Go to OTHER FLOW CHART (Power Seat Position is not Memorized)

OK

4.

CHECK SEAT POSITION RESTORING FUNCTION

(a) Under each of the following conditions, check that the seat restoring function operates by pressing the M1 switch or M2 switch (See page ).

  • Turn the ignition switch is off.
  • Turn the ignition switch to ON, and shift lever in P.*1
  • Turn the ignition switch is off within 180 seconds after the driver door is closed and opened.*2
  • Turn the ignition switch is off within 60 seconds after the driver door is opened and closed.*3
Result

Result

Proceed to

Seat restoring function does not operate at all.

A

Seat restoring function does not operate when the condition is [*1].

B

  • Seat restoring function does not operate when the condition is [*2].
  • Seat restoring function does not operate when the condition is [*3].

C

B

GO TO STEP 10

C

GO TO STEP 11

A

5.

READ VALUE USING TECHSTREAM (SEAT MEMORY)

(a) Perform the seat position memorized function for the M1 switch and M2 switch (See page ).

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

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

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

Driver Seat

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Seat Memory No1

Seat position memorized with M1 switch / Mem or Not Mem

Mem: Memorized

Not Mem: Not memorized

-

Seat Memory No2

Seat position memorized with M2 switch / Mem or Not Mem

Mem: Memorized

Not Mem: Not memorized

-

OK:

Mem appears on the Techstream screen.

NG

Go to OTHER FLOW CHART (Power Seat Position is not Memorized)

OK

6.

REPLACE OUTER MIRROR CONTROL ECU ASSEMBLY

(a) Temporarily replace the outer mirror control ECU assembly with a new or normally functioning one (See page ).

NEXT

7.

CHECK SEAT POSITION RESTORING FUNCTION

(a) Perform a seat position restoring function (See page ).

(b) Check that the buzzer sounds for 0.1 seconds and the seat automatically moves to the memorized position.

NOTICE:

  • The seat position will not return to the memorized position if 2 seat memory switches are pressed simultaneously.
  • If a restoring operation has failed, release all switches. The seat memory restoring function does not operate unless the switches are released.

OK:

Seat position restoring function operates normally.

OK

END (OUTER MIRROR CONTROL ECU ASSEMBLY WAS DEFECTIVE)

NG

8.

REPLACE 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 ).

NEXT

9.

CHECK SEAT POSITION RESTORING FUNCTION

(a) Perform a seat position memory function (See page ).

(b) Check that the buzzer sounds for 0.1 seconds and the seat automatically moves to the memorized position.

NOTICE:

  • The seat position will not return to the memorized position if 2 seat memory switches are pressed simultaneously.
  • If a restoring operation has failed, release all switches. The seat memory restoring function does not operate unless the switches are released.

OK:

Seat position restoring function operates normally.

OK

END (POSITION CONTROL ECU AND SWITCH ASSEMBLY WAS DEFECTIVE)

NG

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

10.

READ VALUE USING TECHSTREAM (P SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream 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

P Switch

Park state signal / ON or OFF

ON: Shift lever in P

OFF: Shift lever in a position other than P

-

OK:

On the Techstream screen, the item changes between ON and OFF according to the above.

Result

Result

Proceed to

OK

A

NG (for AB60E)

B

NG (for AB60F)

C

A

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

B

Go to AUTOMATIC TRANSMISSION SYSTEM

C

Go to AUTOMATIC TRANSMISSION SYSTEM

11.

READ VALUE USING TECHSTREAM (D DOOR COURTESY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

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

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

Main Body

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

D Door Courtesy

Front door courtesy light switch assembly signal / ON or OFF

ON: Driver door open

OFF: Driver door closed

-

OK:

On the Techstream screen, the item changes between ON and OFF according to the above.

OK

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

NG

Go to LIGHTING SYSTEM

    Parts Location

    Power Seat Position is not Memorized

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