Toyota Venza: Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL) (P0741)

Toyota Venza Service Manual / U660e Automatic Transmission / Transaxle / Automatic Transaxle System / Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL) (P0741)

SYSTEM DESCRIPTION

The TCM uses signals from the throttle position sensor, air-flow meter, turbine (input) speed sensor, intermediate (counter gear) speed sensor and crankshaft position sensor to help determine the engagement timing of the lock-up clutch. The TCM monitors the engagement of the clutch using the turbine (input) speed sensor, intermediate (counter gear) speed sensor and crankshaft position sensor.

Then the TCM compares the engagement condition of the lock-up clutch with the lock-up schedule in the TCM memory to detect shift solenoid valve SL, valve body and torque converter mechanical problems.

DTC No.	DTC Detection Condition	Trouble Area
P0741	When both of the following are detected (2-trip detection logic): Lock-up does not occur when requested. Transmission fluid pressure switch No. 3 is ON.	Shift solenoid valve SL remains closed Valve body is blocked Torque converter assembly Automatic transaxle (clutch, brake or gear etc.) Line pressure is too low

MONITOR DESCRIPTION

Torque converter lock-up is controlled by the TCM based on the speed sensor (NT), speed sensor (NC), engine rpm, engine load, engine temperature, vehicle speed, transmission fluid temperature, and gear selection. The TCM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to the input turbine rpm (NT). The TCM calculates the actual transmission gear by comparing the input turbine rpm (NT) to the counter gear rpm (NC). When conditions are appropriate, the TCM requests "lock-up" by applying control voltage to shift solenoid SL. When SL is turned on, it applies pressure to the lock-up relay valve and locks the torque converter.

If the TCM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the TCM interprets this as a fault in shift solenoid valve SL or lock-up system performance. The TCM will turn on the MIL and store the DTC.

HINT:

Example:

When any of the following is met, the system judges it as a malfunction.

There is a difference in rotation (speed) between the input side (engine speed) and output side (input turbine speed) of the torque converter when the TCM commands lock-up.
(Engine speed is at least 70 rpm greater than the input turbine speed.)

MONITOR STRATEGY

Related DTCs	P0741: Shift solenoid valve SL OFF malfunction Shift solenoid valve SL ON malfunction
Required sensors/Components	Shift solenoid valve SL, Speed sensor (NT), Speed sensor (NC), Crankshaft position sensor (NE), Throttle position sensor (VPA1), Mass air flow sensor (MAF), Transmission temperature sensor (THO1), Engine coolant temperature sensor (ECT)
Frequency of operation	Continuous
Duration	OFF malfunction 3.5 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) P2759 (Shift solenoid valve SLU circuit) P2769, P2770 (Shift solenoid valve SL 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)
ECT (Engine coolant temperature)	40°C (104°F) or more
Spark advance from Max. retard timing by KCS control	0°CA or more
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
Shift solenoid valve SLU circuit	No circuit malfunction
Shift solenoid valve SL 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
TCM selected gear	Not 1st
Vehicle speed	15.5 mph (25 km/h) or more
Turbine speed/Output speed (NT/NO) with 1st	3.304 to 7.724
Turbine speed/Output speed (NT/NO) with 2nd	1.901 to 2.340
Turbine speed/Output speed (NT/NO) with 3rd	1.399 to 1.649
Turbine speed/Output speed (NT/NO) with 4th	0.998 to 1.138
Turbine speed/Output speed (NT/NO) with 5th	0.705 to 0.836
Turbine speed/Output speed (NT/NO) with 6th	0.568 to 0.695

TYPICAL MALFUNCTION THRESHOLDS

OFF malfunction:

Following conditions are met	(a) and (b)
(a) Engine Speed - Turbine speed	70 rpm or more
(b) Transmission fluid pressure switch	ON

CAUTION / NOTICE / HINT

NOTICE:

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

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.

1. PERFORM ACTIVE TEST

(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.

Tester Display	Test Part	Control Range	Diagnostic Note
Activate the Lock Up	[Test Details] Controls the shift solenoid SLU and SL to set the automatic transaxle to the lock-up condition. [Vehicle Condition] Vehicle speed: 60 km/h (37 mph) or more	[Lock-up] 0: OFF 1: ON	Possible to check SLU and SL solenoid operation.

Tester Display

Test Part

Control Range

Diagnostic Note

Activate the Lock Up

[Test Details]

Controls the shift solenoid SLU and SL to set the automatic transaxle to the lock-up condition.

[Vehicle Condition]

Vehicle speed: 60 km/h (37 mph) or more

[Lock-up]

0: OFF

1: ON

Possible to check SLU and SL solenoid operation.

HINT:

This test can be conducted when the vehicle speed is 60 km/h (37 mph) or more.

(h) Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.

HINT:

When changing the accelerator pedal opening angle while driving, if the engine speed does not change, lock-up is on.
Slowly release, but not fully, the accelerator pedal in order to decelerate. (Fully releasing the pedal will close the throttle valve and lock-up may be turned off.)

PROCEDURE

1.	CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0741)

(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 "P0741" is output	A
"P0741" and other DTCs	B

HINT:

If any other codes besides "P0741" are output, perform the troubleshooting for those DTCs first.

GO TO DTC CHART

2.	CHECK TRANSMISSION WIRE

(a) Remove the TCM from the transaxle.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
6 (SL) - Body ground	20°C (68°F)	11 to 15 Ω

GO TO STEP 4

3.	INSPECT SHIFT SOLENOID VALVE SL (RESISTANCE)

(a) Remove shift solenoid valve SL.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Solenoid Connector (SL) - Solenoid Body (SL)	20°C (68°F)	11 to 15 Ω

Text in Illustration

*1	Shift Solenoid Valve SL

REPLACE TRANSMISSION WIRE

REPLACE SHIFT SOLENOID VALVE SL

4.	INSPECT SHIFT SOLENOID VALVE SL (OPERATION)

(a) Remove shift solenoid valve SL.

(b) Connect a battery positive (+) lead to the terminal of the solenoid valve connector, and a negative (-) lead to the solenoid body. Then check that the valve moves and makes an operating sound.

OK:

Valve moves and makes an operating sound.

Text in Illustration

*1	Shift Solenoid Valve SL

REPLACE SHIFT SOLENOID VALVE SL

5.	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 TRANSMISSION VALVE BODY ASSEMBLY

6.	INSPECT TORQUE CONVERTER ASSEMBLY

(a) Check the torque converter assembly (See page ).

OK:

The torque converter operates normally.

REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY

REPLACE TORQUE CONVERTER ASSEMBLY

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