Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2) (P0778)

Toyota Tacoma 2015-2018 Service Manual / Ac60e Automatic Transmission / Transaxle / Automatic Transmission System(for 2tr-fe) / Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2) (P0778)

DESCRIPTION

Changing from 1st to 6th is performed by the ECM turning shift solenoid valves SL1, SL2, SL3 and SL4 on and off. If an open or short circuit occurs in any of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated (See page ).

DTC No.

DTC Detection Condition

Trouble Area

P0778

An open or short circuit (output signal duty is 0% or 100%) is detected by the ECM in the shift solenoid valve SL2 circuit while driving and shifting gears (SL2 output signal duty is more than 3% and less than 100% under normal conditions) (1 trip detection logic).
  • Open or short in shift solenoid valve SL2 circuit
  • Shift solenoid valve SL2
  • ECM

MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL2 circuit. The ECM commands gear shifts by turning the shift solenoid valves on or off. When there is an open or short circuit in any of the shift solenoid valve circuits, the ECM detects the problem and illuminates the MIL and stores the DTC. The ECM also performs the fail-safe function and turns the other normal shift solenoid valves on or off. (In case of an open or short circuit, the ECM stops sending current to the circuit.)

While driving and shifting gears, if the ECM detects an open or short in the shift solenoid valve SL2 circuit, the ECM determines there is a malfunction (See page MONITOR STRATEGY ).

MONITOR STRATEGY

Related DTCs

P0778: Shift solenoid valve SL2/Range check

Required sensors/Components

Shift solenoid valve SL2

Frequency of operation

Continuous

Duration

1 sec.

MIL operation

Immediately

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All:

The monitor will run whenever the following DTCs are not stored

None

Solenoid current cut status

Not cut

Ignition switch

ON

Starter

OFF
Condition (A):

Battery voltage

12 V or higher
Condition (B):

Battery voltage

10 V or higher, and below 12 V

Target current

Below 0.75 A
Condition (C):

Battery voltage

8 V or higher

Target current

0.25 A or higher

TYPICAL MALFUNCTION THRESHOLDS

One of the following conditions is met: Condition (A), (B) or (C)

Condition (A) and (B):

Output duty cycle

100% or more
Condition (C):

Output duty cycle

0% or less

COMPONENT OPERATING RANGE

Output duty cycle

More than 3%, and less than 100%

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

NOTICE:

  • Perform the universal trip to clear permanent DTCs (See page Perform registration and/or initialization when parts related to the ).
  • Perform registration and/or initialization when parts related to the automatic transmission are replaced (See page ).

HINT:

  • The following table shows normal operation of the shift solenoid valve SL2 when the shift lever is in D:

    ECM commanded gear

    1st

    2nd

    3rd

    4th

    5th

    6th

    Shift solenoid valve SL2

    OFF

    OFF

    OFF

    ON

    ON

    ON
  • After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
    1. Perform the D Position Shift Test in Road Test.
    2. Check for DTCs again (See page ).

PROCEDURE

1.

INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL2)

(a) Disconnect the E1 transmission wire connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

15 (SL2+) - 16 (SL2-)

20°C (68°F)

5.0 to 5.6 Ω

15 (SL2+) - Body ground

Always

10 kΩ or higher

16 (SL2-) - Body ground

Always

10 kΩ or higher
Text in Illustration

*a

Component without harness connected

(Transmission Wire)
NG

GO TO STEP 3

OK

2.

CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)

(a) Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

E19-7 (SL2+) - E19-6 (SL2-)

20°C (68°F)

5.0 to 5.6 Ω

E19-7 (SL2+) - Body ground

Always

10 kΩ or higher

E19-6 (SL2-) - Body ground

Always

10 kΩ or higher
Text in Illustration

*a

Rear view of wire harness connector

(to ECM)
OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.

INSPECT SHIFT SOLENOID VALVE SL2

(a) Remove shift solenoid valve SL2 (See page ).

(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

*1

Shift Solenoid Valve SL2
OK

REPLACE TRANSMISSION WIRE

NG

REPLACE SHIFT SOLENOID VALVE SL2

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Other materials:

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