Last Modified: 11-29-2007 1.6 C
Service Category: Drivetrain Section: Automatic Transmission/Transaxle
Model Year: 2008 Model: Sequoia Doc ID: RM000000W8G04NX
Title: A750E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: DESCRIPTION (2008 Sequoia)

DTC

P0778

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

DESCRIPTION

Shifting from 1st to 5th is performed in combination with the "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, S1, S2 and SR which are controlled by the ECM. If an open or short circuit occurs in one of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly A750E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART (2008 Sequoia) .

DTC No.

DTC Detection Condition

Trouble Area

P0778

  • ECM detects open or short in shift solenoid valve SL2 circuit while driving and shifting gears. (1-trip detection logic)
  • Output signal duty is 100%.

HINT:

SL2 output signal duty is less than 100% under normal condition.

  • 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/OFF". When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. The ECM performs the fail-safe function and turns the other shift solenoid valves in good condition "ON/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 A750E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART (2008 Sequoia) .

MONITOR STRATEGY

Related DTCs

P0778: Shift solenoid valve SL2/Range check

Required sensors/Components

Shift solenoid valve SL2

Frequency of operation

Continuous

Duration

1 second

MIL operation

Immediately

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever the following DTCs are not present

None

All of the following conditions are met: Condition (A) and (B)

Condition (A)

Battery voltage

12 V or more

Ignition switch

ON

Starter

OFF

Condition (B)

Battery voltage

10 V or more and less than 12 V

CPU commanded duty

Less than 75%

Ignition switch

ON

Starter

OFF

TYPICAL MALFUNCTION THRESHOLDS

Output signal duty

100%

COMPONENT OPERATING RANGE

Output signal duty

More than 3% and less than 100%

WIRING DIAGRAM



INSPECTION PROCEDURE

HINT:

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

Shift solenoid valve SL2

ON

ON

ON

ON

OFF

PROCEDURE

1.

INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL2)


(a) Disconnect the D63 transmission wire connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

11 (SL2+) - 3 (SL2-)

20°C (68°F)

5.0 to 5.6 Ω

11 (SL2+) - Body ground

Always

10 kΩ or higher

3 (SL2-) - Body ground

Always

10 kΩ or higher

OK

2.

CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)


(a) Disconnect the D56 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D56-12 (SL2+) - D56-13 (SL2-)

20°C (68°F)

5.0 to 5.6 Ω

D56-12 (SL2+) - Body ground

Always

10 kΩ or higher

D56-13 (SL2-) - Body ground

Always

10 kΩ or higher

OK

3.

INSPECT SHIFT SOLENOID VALVE SL2


(a) Remove the 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) Connect the battery positive (+) lead with a 21 W bulb to terminal 1 and the negative (-) lead to terminal 2 of the solenoid valve connector. Then check that the valve moves and makes an operating noise.

OK:

Valve moves and makes an operating noise.

OK