Toyota Tundra Service Manual: Shift Solenoid "D" Performance (Shift Solenoid Valve S4) (P0766,P0776)

Toyota Tundra Service Manual / Engine, Hybrid System / A760e Automatic Transmission / Transaxle / Automatic Transmission System / Shift Solenoid "D" Performance (Shift Solenoid Valve S4) (P0766,P0776)

DESCRIPTION

The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th, 5th or 6th gear).

Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body and automatic transmission (clutch, brake, gear, etc.).

DTC Code

DTC Detection Condition

Trouble Area

P0766

  • S4 stuck OFF malfunction or brake control valve malfunction*:
  • Shifting to 5th and 6th gears is impossible.
  • The ECM determines there is a malfunction when the following conditions are both met (2-trip detection logic):

(a) When the ECM directs the transmission to switch to 5th gear, the actual gear is shifted to 4th.

(b) When the ECM directs the transmission to switch to 6th gear, the actual gear is shifted to 4th.

  • Shift solenoid valve S4 remains closed
  • Shift solenoid valve SLT remains open or closed
  • Valve body is blocked (brake control valve)
  • Automatic transmission (clutch, brake, gear, etc.)

P0776

  • SL2 stuck ON malfunction or brake control valve malfunction*:
  • Shifting to 5th and 6th gears is impossible.
  • The ECM determines there is a malfunction when the following conditions are both met (2-trip detection logic):

(a) When the ECM directs the transmission to switch to 5th gear, the actual gear is shifted to 4th.

(b) When the ECM directs the transmission to switch to 6th gear, the actual gear is shifted to 4th.

  • Shift solenoid valve SL2 remains closed
  • Shift solenoid valve SLT remains open or closed
  • Valve body is blocked (brake control valve)
  • Automatic transmission (clutch, brake, gear, etc.)

HINT:

  • Gear positions in the event of a solenoid valve mechanical problem:

    ECM gear shift command

    1st

    2nd

    3rd

    4th

    5th

    6th

    *: Actual gear position under malfunction

    1st

    2nd

    3rd

    4th

    4th

    4th

  • Gear position during fail-safe operation:

    If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below.

    Gear position under normal conditions

    1st

    2nd

    3rd

    4th

    5th

    6th

    *: Actual gear position under fail-safe mode

    1st

    2nd

    3rd

    3rd

    3rd

    3rd

MONITOR DESCRIPTION

This DTC indicates a "stuck OFF malfunction" of the shift solenoid valve S4, a "stuck ON malfunction" of the shift solenoid valve SL2, or a brake control valve malfunction. The ECM commands gear shifts by turning the shift solenoid valves ON/OFF. When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores the DTCs.

MONITOR STRATEGY

Related DTCs

P0766: Shift solenoid valve S4/Functional check

P0776: Shift solenoid valve SL2/Functional check

Required sensors/Components

Shift solenoid valve S4, Speed sensor (NT), Speed sensor (SP2), Crankshaft position sensor (NE)

Frequency of operation

Continuous

Duration

0.4 seconds

MIL operation

2 driving cycles

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever the following DTCs are not present

P0717 (Turbine speed sensor circuit)

P0722 (Output Speed Sensor circuit)

P0710, P0712, P0713, P2740, P2742, P2743 (ATF temperature sensor circuit)

P0973, P0974 (Shift solenoid valve S1 circuit)

P0976, P0977 (Shift solenoid valve S2 circuit)

P0979, P0980 (Shift solenoid valve S3 circuit)

P0982, P0983 (Shift solenoid valve S4 circuit)

P0985, P0986 (Shift solenoid valve SR circuit)

P0748 (Shift solenoid valve SL1 circuit)

P0778 (Shift solenoid valve SL2 circuit)

P0115, P0116, P0117, P0118, P011B (ECT (Engine coolant temperature) sensor circuit)

P0327, P0328, P032C, P032D (KCS sensor circuit)

ETCS (Electric Throttle Control System)

Not system down

Transmission position

"D"

Duration time from shifting "N" to "D"

4 seconds or more

ECT

40°C (104°F) or higher

Spark advance from max. retard timing by KCS control

0° crankshaft angle or more

Engine

Starting

Calculated load value

7.75% or more (A/C off)

7.75% or more (A/C on)

Input speed/output speed (NT/NO)

NT: Input (Turbine) speed

NO: Internal counter shaft speed

3.30 to 7.50

or

1.91 to 2.35

or

1.28 to 1.53

or

0.93 to 1.07

or

0.65 to 0.79

or

0.51 to 0.65

P0766 OFF Malfunction (A) and P0776 ON Malfunction (A)

ECM selected gear

5th

Vehicle speed

2 km/h (1.2 mph) or more

Throttle valve opening angle

5% or more at 2000 rpm

(Conditions vary with engine speed)

P0766 OFF Malfunction (B) and P0776 ON Malfunction (B)

ECM selected gear

6th

Vehicle speed

2 km/h (1.2 mph) or more

Throttle valve opening angle

5% or more at 2000 rpm

(Conditions vary with engine speed)

TYPICAL MALFUNCTION THRESHOLDS

[OFF malfunction]
  • Both of the following conditions are met: OFF malfunction (A) and (B)
P0766 OFF Malfunction (A)

Turbine speed / Output speed (NT / NO)

0.93 or more, and 1.07 or less

(This means actual gear is 4th)

P0766 OFF Malfunction (B)

Turbine speed / Output speed (NT / NO)

0.93 or more, and 1.07 or less

(This means actual gear is 4th)

[ON malfunction]
  • Both of the following conditions are met: ON malfunction (A) and (B)
P0776 ON Malfunction (A)

Turbine speed / Output speed (NT / NO)

0.93 or more, and 1.07 or less

(This means actual gear is 4th)

P0776 ON Malfunction (B)

Turbine speed / Output speed (NT / NO)

0.93 or more, and 1.07 or less

(This means actual gear is 4th)

CAUTION / NOTICE / HINT

NOTICE:

Perform the universal trip to clear permanent DTCs (See page ).

1. ACTIVE TEST

HINT:

Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

(a) Warm up the engine.

(b) Turn the ignition switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Engine and ECT / Active Test.

(g) According to the display on the Techstream, perform the Active Test.

HINT:

While driving, the shift position can be forcibly changed with the Techstream.

Comparing the shift position commanded by the Active Test with the actual shift position enables you to confirm the problem (See page ).

Engine and ECT

Tester Display

Test Part

Control Range

Diagnostic Note

Control the Shift Position

Operate shift solenoid valves and set each shift position

  • Press "→" button: Shift up
  • Press "←" button: Shift down

Possible to check operation of the shift solenoid valves.

[Vehicle Condition]

50 km/h (30 mph) or less

HINT:

  • This test can be conducted when the vehicle speed is 50 km/h (30 mph) or less.
  • The 4th to 5th and 5th to 6th up-shifts must be performed with the accelerator pedal released.
  • The 6th to 5th and 5th to 4th down-shifts must be performed with the accelerator pedal released.
  • Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.
  • The shift position commanded by the ECM is shown in the Data List display on the Techstream.
  • The shift solenoid valve SL2 turns ON/OFF normally when the shift lever is in D.

    ECM gear shift command

    1st

    2nd

    3rd

    4th

    5th

    6th

    Shift solenoid valve S4

    OFF

    OFF

    OFF

    OFF

    ON

    ON

    Shift solenoid valve SL2

    ON

    ON

    ON

    ON

    OFF

    OFF

PROCEDURE

1.

CHECK DTC OUTPUT (IN ADDITION TO DTCS P0766 AND P0776)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read the DTCs using the Techstream.

Result

Result

Proceed to

Only P0766 and P0776 are output

A

P0766, P0776 and other DTCs are output

B

HINT:

If any other codes besides P0766 and P0776 are output, perform troubleshooting for those DTCs first.

B

GO TO DTC CHART

A

2.

PERFORM ACTIVE TEST USING TECHSTREAM (SHIFT SOLENOID VALVE SLT)

NG

REPLACE SHIFT SOLENOID VALVE SLT

OK

3.

INSPECT SHIFT SOLENOID VALVE S4

(a) Remove shift solenoid valve S4.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Shift solenoid valve S4 connector terminal - Shift solenoid valve S4 body

20°C (68°F)

11 to 15 Ω

(c) Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

OK:

Measurement Condition

Specified Condition

  • Battery positive (+) → Shift solenoid valve S4 connector
  • Battery negative (-) → Shift solenoid valve S4 body

Valve moves and makes an operating noise

Text in Illustration

*a

Component without harness connected

(Shift Solenoid Valve S4)

NG

REPLACE SHIFT SOLENOID VALVE S4

OK

4.

INSPECT SHIFT SOLENOID VALVE SL2

(a) Remove shift solenoid valve SL2.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1 - 2

20°C (68°F)

5.0 to 5.6 Ω

(c) Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

OK:

Measurement Condition

Specified Condition

  • Battery positive (+) with a 21 W bulb → Terminal 1
  • Battery negative (-) → Terminal 2

Valve moves and makes an operating noise

Text in Illustration

*a

Component without harness connected

(Shift Solenoid Valve SL2)

NG

REPLACE SHIFT SOLENOID VALVE SL2

OK

5.

INSPECT TRANSMISSION VALVE BODY ASSEMBLY

OK

REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY

NG

REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY

    Shift Solenoid "C" Performance (Shift Solenoid Valve S3) (P0761)

    Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2) (P0778)

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