Toyota Venza: Pressure Control Solenoid "A" Performance (Shift Solenoid Valve SL1) (P0746)

Toyota Venza Service Manual / U660e Automatic Transmission / Transaxle / Automatic Transaxle System / Pressure Control Solenoid "A" Performance (Shift Solenoid Valve SL1) (P0746)

SYSTEM DESCRIPTION

The TCM uses the vehicle speed signal and signals from the transmission speed sensors (NC, NT) to detect the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear).

Then the TCM compares the actual gear with the shift schedule in the TCM memory to detect mechanical problems of the shift solenoid valves and valve body.

DTC No.	DTC Detection Condition	Trouble Area
P0746	The engine revs freely when 1st, 2nd, 3rd, or 4th gear is commanded (2-trip detection logic). When either of the following is detected twice (2-trip detection logic): When 5th gear is commanded, 4th gear is engaged. When 6th gear is commanded, 4th gear is engaged	Shift solenoid valve SL1 remains open or closed Valve body is blocked Automatic transaxle (clutch, brake or gear etc.)

DTC No.

DTC Detection Condition

Trouble Area

P0746

The engine revs freely when 1st, 2nd, 3rd, or 4th gear is commanded (2-trip detection logic).

When either of the following is detected twice (2-trip detection logic):

When 5th gear is commanded, 4th gear is engaged.
When 6th gear is commanded, 4th gear is engaged

Shift solenoid valve SL1 remains open or closed
Valve body is blocked
Automatic transaxle (clutch, brake or gear etc.)

MONITOR DESCRIPTION

The TCM commands gear shifts by turning the shift solenoid valves on and off. According to the input shaft revolution (speed), intermediate (counter) shaft revolution (speed) and output shaft revolution (speed), the TCM detects the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear). When the gear commanded by the TCM and the actual gear are not the same, the TCM illuminates the MIL and stores the DTC.

MONITOR STRATEGY

Related DTCs	P0746: Shift solenoid valve SL1 OFF malfunction Shift solenoid valve SL1 ON malfunction
Required sensors/Components	Shift solenoid valve SL1, Speed sensor (NT), Speed sensor (NC), Crankshaft position sensor (NE)
Frequency of operation	Continuous
Duration	ON malfunction: 0.8 sec. OFF malfunction: 0.5 sec.
MIL operation	2 driving cycles
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

ALL:

The monitor will run whenever this DTC is not present. (Not circuit malfunction)	P0712, P0713 (ATF temperature sensor circuit (TFT sensor)) P0115, P0117, P0118 (ECT sensor circuit) P0715, P0717 (Turbine speed sensor circuit) P0791, P0793 (Intermediate shaft speed sensor circuit) P0748 (Shift solenoid valve SL1 circuit) P0778 (Shift solenoid valve SL2 circuit) P0798 (Shift solenoid valve SL3 circuit) P2810 (Shift solenoid valve SL4 circuit) P0327, P0328, P0332, P0333 (KCS sensor circuit) P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0604, P0606, P060A, P060B, P060D, P060E, P0657, P1607, P2102, P2103, P2111, P2112, P2118, P2119, P2135 ((ETCS) Electronic throttle control system) U0100 (CAN communication system)
Transmission range	"D"
TFT (Transmission fluid temperature)	-10°C (14°F) or more
TFT (Transmission fluid temperature) sensor circuit	No circuit malfunction
ECT (Engine coolant temperature) sensor circuit	No circuit malfunction
Turbine speed sensor circuit	No circuit malfunction
Intermediate shaft speed sensor circuit	No circuit malfunction
Shift solenoid valve SL1 circuit	No circuit malfunction
Shift solenoid valve SL2 circuit	No circuit malfunction
Shift solenoid valve SL3 circuit	No circuit malfunction
Shift solenoid valve SL4 circuit	No circuit malfunction
(KCS) Knock control sensor circuit	No circuit malfunction
(ETCS) Electronic throttle control system	Not system down
CAN communication system	Not system down
Engine	Starting

OFF malfunction:

TCM selected gear	1st, 2nd, 3rd or 4th
TCM indicated pressure value of SL1	1,200 kPa
Throttle valve opening angle	3% or more

ON malfunction:

TCM selected gear	5th or 6th
Vehicle speed	1.2 mph (2 km/h) or more
ETC (Engine coolant temperature)	40°C (104°F) or more
Throttle valve opening angle	4.5% or more at engine speed 2,000 rpm (Varies with engine speed)

TYPICAL MALFUNCTION THRESHOLDS

Either of the following conditions is met:

OFF malfunction:

Turbine speed - Output speed x Gear ratio

1,000 rpm or more

ON malfunction:

Input (turbine) speed/Intermediate shaft speed when output speed less than 1,000 rpm

0.998 to 1.138

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.	CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0746)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

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

(e) Read the DTCs using the Techstream.

Display (DTC Output)	Proceed to
Only "P0746" is output	A
"P0746" and other DTCs	B

HINT:

If a solenoid is stuck OFF, DTCs for several solenoids including the malfunctioning solenoid will be detected.

GO TO STEP 3

2.	PERFORM ACTIVE TEST USING TECHSTREAM

NOTICE:

This test should always be performed with at least 2 people.

(a) Warm up the engine.

(b) Turn the ignition switch off.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

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

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

HINT:

Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem (See page ).

Item	Test Details	Diagnostic Note
Control the Shift Position	[Test Details] Operates the shift solenoid valves to allow gears to selected manually. [Others] Press "→" button: Upshift occurs Press "←" button: Downshift occurs	Can be used to check the operation of the shift solenoid valves.

Item

Test Details

Diagnostic Note

Control the Shift Position

[Test Details]

Operates the shift solenoid valves to allow gears to selected manually.

[Others]

Press "→" button: Upshift occurs
Press "←" button: Downshift occurs

Can be used to check the operation of the shift solenoid valves.

NOTICE:

This test can be conducted when the vehicle is stopped.
When shifting gears using the Active Test function, do not operate the accelerator pedal for 2 seconds before and after shifting gears.

HINT:

The gear commanded by the TCM is shown in the Data List / Shift Status display on the Techstream.

(h) Check the vehicle speed and the gear when the engine speed is 1000 rpm.

HINT:

Because the torque converter has not engaged, it may be difficult to obtain the speeds specified in 4th, 5th, and 6th gear, however a difference of speed should still be evident following each gear change.

Standard:

1st	2nd	3rd	4th	5th	6th
8 to 12 km/h (5 to 7.5 mph)	15 to 19 km/h (9.3 to 11.8 mph)	21 to 25 km/h (13.0 to 15.5 mph)	31 to 35 km/h (19.3 to 21.7 mph)	44 to 48 km/h (27.3 to 29.8 mph)	52 to 56 km/h (32.3 to 34.8 mph)

(i) Compare the TCM commanded gear and the actual gear.

Actuator Gear during Malfunction		TCM Commanded Gear						Proceed to
Actuator Gear during Malfunction		1st	2nd	3rd	4th	5th	6th	Proceed to
Shift solenoid SL1	Stuck ON	1st	2nd	3rd	4th	4th	4th	A
Shift solenoid SL1	Stuck OFF	N*1	N*1	N*1	N*1	5th	6th	A
Shift solenoid SL2	Stuck ON	4th	4th	4th	4th	5th	6th	B
Shift solenoid SL2	Stuck OFF	1st	2nd	3rd	1st	N*1	N*1	B
Shift solenoid SL3	Stuck ON	2nd	2nd	3rd	4th	5th	6th	C
Shift solenoid SL3	Stuck OFF	1st	1st	3rd	4th	5th	N*1	C
Shift solenoid SL4	Stuck ON*3	3rd	3rd	3rd	4th	5th	5th	D
Shift solenoid SL4	Stuck OFF	1st	2nd	1st	4th	N*1	6th	D
Shift solenoid SLT	Stuck ON	N*2	N*2	N*2	N*2	N*2	N*2	E
Shift solenoid SLT	Stuck OFF*3	1st	2nd	3rd	4th	5th	6th	E

HINT:

*1: Neutral
*2: If shift solenoid SLT is stuck on, the line pressure will be low. Therefore, the amount of torque that can be transmitted by each gear is lower than the normal limit. When the engine power exceeds this lowered limit, the engine speed will increase freely.
*3: When shift solenoid SLT is stuck off, gear shifting is normal.

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SL2) PERFORMANCE DTC P0776)

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SL3) PERFORMANCE DTC P0796)

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SL4) PERFORMANCE DTC P2808)

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SLT) PERFORMANCE DTC P2714)

3.	INSPECT SHIFT SOLENOID VALVE SL1

(a) Remove shift solenoid valve SL1.

(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

Text in Illustration

*1	Shift Solenoid Valve SL1

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

OK:

Valve moves and makes an operating sound.

REPLACE SHIFT SOLENOID VALVE SL1

4.	INSPECT TRANSMISSION VALVE BODY ASSEMBLY

(a) Check the transmission valve body assembly (See page ).

OK:

There are no foreign objects on each valve and they operate smoothly.

REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY

REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY

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