Dtc P0741 Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve Sl)
SYSTEM DESCRIPTION
MONITOR DESCRIPTION
INSPECTION PROCEDURE
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0741)
INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL)
INSPECT SHIFT SOLENOID VALVE SL (OPERATION)
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
INSPECT TORQUE CONVERTER ASSEMBLY
INSPECT SHIFT SOLENOID VALVE SL (RESISTANCE)
DTC P0741 Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL) |
SYSTEM DESCRIPTION
The ECM uses signals from the throttle position sensor, air-flow meter, transmission revolution sensor (NT), transmission revolution sensor (SP2) and crankshaft position sensor to help determine the engagement timing of the lock-up clutch. The ECM monitors the engagement of the clutch using the transmission revolution sensor (NT), transmission revolution sensor (SP2) and crankshaft position sensor.Then the ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect shift solenoid valve SL, transmission valve body assembly and torque converter assembly mechanical problems.DTC No.
| DTC Detection Condition
| Trouble Area
|
P0741
| Lock-up does not occur when requested (2 trip detection logic).
| - Shift solenoid valve SL remains closed
- Transmission wire
- Transmission valve body assembly is blocked
- Torque converter assembly
- Automatic transmission assembly (clutch, brake or gear etc.)
- Line pressure is too low
|
MONITOR DESCRIPTION
Torque converter lock-up is controlled by the ECM based on the transmission revolution sensor (NT), transmission revolution sensor (SP2), engine speed, engine load, engine temperature, vehicle speed, transmission fluid temperature, and gear selection. The ECM determines the lock-up status of the torque converter by comparing the engine speed (NE) to the input turbine speed (NT). The ECM calculates the actual transmission gear by comparing the input turbine speed (NT) to the output shaft speed (SP2). When conditions are appropriate, the ECM requests "lock-up" by applying control voltage to shift solenoid valve SL. When shift solenoid valve SL is turned on, it applies pressure to the lock-up relay valve and locks the torque converter.If the ECM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the ECM interprets this as a fault in shift solenoid valve SL or lock-up system performance. The ECM will illuminate 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 ECM commands lock-up.
(Engine speed is at least 70 rpm more than the input turbine speed.)
- There is no difference in rotation speed between the input side (engine speed) and output side (input turbine speed) of the torque converter when the ECM commands lock-up off.
(The difference between engine speed and input turbine speed is less than 35 rpm.)
INSPECTION PROCEDURE
- NOTICE:
- Perform registration and/or initialization when parts related to the automatic transmission are replaced (LandCruiser RM000000O7H0HRX.html).
- HINT:
- After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
- Perform the Lock-up Function in Road Test (LandCruiser RM000000W790SFX.html).*1
- Turn the engine switch off.
- Perform step (*1) again.
- Check for DTCs again (LandCruiser RM000000W7711JX.html).
- HINT:
- Using the GTS 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.
Warm up the engine.
Turn the engine switch off.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test.
According to the display on the GTS, perform the Active Test.
Engine and ECTTester Display
| Test Part
| Control Range
| Diagnostic Note
|
Activate the Lock Up
| Controls the shift solenoid valves SLU and SL to set the automatic transmission to the lock-up condition.
| ON/OFF
| Can be used to check shift solenoid valves SLU and SL operation.
[Vehicle Condition]
- Throttle valve opening angle: Less than 10%
- Vehicle speed: 80 km/h (50 mph) or more
|
- HINT:
- This test can be conducted when the vehicle speed is 80 km/h (50 mph) or more.
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 the accelerator pedal in order to decelerate, but do not fully release the pedal. (Fully releasing the pedal will close the throttle valve and lock-up may be turned off.)
| 1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0741) |
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs using the GTS.
ResultResult
| Proceed to
|
Only DTC P0741 is output
| A
|
P0741 and other DTCs are output
| B
|
- HINT:
- If any other codes besides P0741 are output, perform the troubleshooting for those DTCs first.
| 2.INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL) |
Disconnect the transmission wire connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
1 (SL) - Body ground
| 20°C (68°F)
| 11 to 15 Ω
|
Text in Illustration*a
| Component without harness connected
(Transmission Wire)
|
| 3.INSPECT SHIFT SOLENOID VALVE SL (OPERATION) |
Remove shift solenoid valve SL (LandCruiser RM000000O9L07IX.html).
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 SL connector
- Battery negative (-) → Shift solenoid valve SL body
| Valve moves and makes an operating noise
|
Text in Illustration*1
| Shift Solenoid Valve SL
|
| 4.INSPECT TRANSMISSION VALVE BODY ASSEMBLY |
Check the transmission valve body assembly (LandCruiser RM000000O9L07IX.html).
- OK:
- There is no foreign matter on each valve and they operate smoothly.
| 5.INSPECT TORQUE CONVERTER ASSEMBLY |
Check the torque converter assembly (LandCruiser RM000000OA102PX.html).
- OK:
- The torque converter operates normally.
| 6.INSPECT SHIFT SOLENOID VALVE SL (RESISTANCE) |
Remove shift solenoid valve SL (LandCruiser RM000000O9L07IX.html).
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
Shift solenoid valve SL connector terminal - Shift solenoid valve SL body
| 20°C (68°F)
| 11 to 15 Ω
|
Text in Illustration*1
| Shift Solenoid Valve SL
|
