P0741
Symptom: CHECK GEARBOX lamp on. Lock-up function disengaged.
Lock-up malfunction
Fault symptoms
CHECK GEARBOX lamp on. Lock-up function disengaged.
Conditions
Difference between engine speed and speed of gearbox input shaft is greater than 100 rpm for 10 seconds.
Diagnosis will not be performed if:
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Engine idling or engine speed greater than 4000 rpm.
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Less than 5 seconds has elapsed since shifting occurred.
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Check the wiring
Intermittent faults may arise due to temporary short circuits or open circuits. Jiggle the wiring harness in several places and in varying directions to reveal any problems in the wiring harness or connectors. Observe the multimeter, Tech 2 or test lamp during the check.
Diagnostic procedure
1 Check the fault symptom.
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See Service Manual 4:2 Automatic Transmission OBD II M1996-.
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Perform diagnosis according to “Road test schedule” and complete the “Diagnosis and test report”, noting any symptoms.
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Are there any fault symptoms?
Continue fault diagnosis of symptom “Mechanical and hydraulic faults” in Service Manual 4:2 Automatic Transmission OBD II M1996-. Continue with step 2.
Check that the input speed sensor is fitted on the gearbox correctly. Continue with step 2.
2 Final check
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Clear the diagnostic trouble code.
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Perform a driving cycle:
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Drive the car at varying loads and engine speeds for 5 minutes.
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Evaluate the driving cycle:
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Check that the malfunction is no longer present after the driving cycle.
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Is the function OK?
The steps taken to rectify the fault were correct.
See “Before changing a control module” in Service Manual 4:2 Automatic Transmission OBD II M1996-.
