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P0741








A246E AUTOMATIC TRANSAXLE: P0741: Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL)

DTC P0741 - Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL)

SYSTEM DESCRIPTION

The ECM uses the signals from the throttle position sensor, Air-flow meter, turbine (input) speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.
Then the ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect a mechanical problems of the shift solenoid valve SL, valve body and torque converter clutch or automatic transaxle (clutch, brake or gear etc.).





MONITOR DESCRIPTION

Based on the signals from the throttle position sensor, the airflow meter and the crankshaft position sensor, the ECM sends a signal to the shift solenoid valve SL to regulate the hydraulic pressure and provide smoother gearshifts. The shift-solenoid valve SL responds to commands from the ECM. The valve controls the lock-up relay valve to perform torque-converter lock-up and flexible lock-up functions.
The ECM compares the engine rpm (NE) signal and the input speed calculated by output speed sensor (output speed) and gear ratio to detect torque converter lock-up. The ECM then compares the lock-up status against the lock-up schedule in the ECM memory. If the ECM does not detect lock-up at the appropriate time, it will conclude that there is a malfunction of shift solenoid SL. The ECM will illuminate the MIL.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All:





OFF malfunction:





ON malfunction:





TYPICAL MALFUNCTION THRESHOLDS

Either of the following conditions is met: OFF malfunction or ON malfunction OFF malfunction:





ON malfunction:

2 detections are necessary per driving cycle:
1st detection; temporary flag ON
2nd detection; pending fault code ON





INSPECTION PROCEDURE

HINT: Performing the Active Test using Techstream allows the relay, VSV, actuator and so on to operate without parts removal. Performing the Active Test as the first step of troubleshooting is one method to shorten labor time.

It is possible to display the Data List during the Active Test.

1. PERFORM ACTIVE TEST
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect Techstream to the DLC3.
(d) Turn the ignition switch to the on position.
(e) Turn on the tester.
(f) Select the item "Enter / Powertrain / Engine and ECT / Active Test".
(g) According to the display on the tester, perform the "Active Test".





HINT:
- This test can be conducted when the vehicle speed is 58 km/h (36 mph) or more.
- This test can be conducted in the 3rd or O/D gear.

(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 Techstream to the DLC3.
(b) Turn the ignition switch to the on position and turn the Techstream main switch on.
(c) When you use Techstream:
Select the item "Powertrain / Engine and ECT / Trouble Codes".
(d) Read the DTCs using Techstream.
Result::





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

B -- GO TO DTC CHART
A -- Continue to next step.
2. INSPECT SHIFT SOLENOID VALVE (SL)





(a) Remove the shift solenoid valve SL.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(c) Connect the positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.
OK:
The solenoid valve makes an operating sound.
NG -- REPLACE SHIFT SOLENOID VALVE (SL)
OK -- Continue to next step.
3. INSPECT TRANSMISSION VALVE BODY ASSEMBLY
OK:
There are no foreign objects on each valve and they operate smoothly.
NG -- REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY
OK -- Continue to next step.
4. INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY
OK:
The torque converter clutch operates normally.
NG -- REPLACE TORQUE CONVERTER CLUTCH ASSEMBLY
OK -- REPAIR AUTOMATIC TRANSAXLE ASSEMBLY