P0744

DTC P0744 A/T TCC S/V Function (Lock-Up)

Description
This malfunction is detected when the A/T does not shift into 5th gear position or the torque converter clutch does not lock-up as instructed by the TCM. This is not only caused by electrical malfunction (circuits open or shorted) but also by mechanical malfunction such as control valve sticking, improper solenoid valve operation, etc.

SDT Reference Value in Data List Mode





On Board Diagnosis Logic
^ This is an 0BD-II self-diagnostic item.
^ Diagnostic trouble code "P0744 A/T TCC S/V FNCTN" with SDT is detected under the following conditions.
^ When A/T cannot perform lock-up even if electrical circuit is good.
^ When TCM detects as irregular by comparing difference value with slip rotation.

Possible Cause
^ Harness or connectors
(The solenoid circuit is open or shorted.)
^ Torque converter clutch solenoid valve
^ Hydraulic control circuit

DTC Confirmation Procedure

CAUTION:
Always drive vehicle at a safe speed.

NOTE:
If "DTC Confirmation Procedure" has been previously performed, always turn ignition switch "OFF" and wait at least 10 seconds before performing the next test.

After the repair, perform the following procedure to confirm the malfunction is eliminated.

WITH SDT
1. Start engine.
2. Select "Data list" mode for "AT" with SDT.
3. Drive vehicle and maintain the following conditions for at least 30 consecutive seconds.
ACCELE POSI: More than 1.0/8
SLCT LVR POSI: "D" position
TCC SOLENOID: 0.4 - 0.6 A
VEHICLE SPEED: 80 km/h (50 MPH) or more
Driving locations: Driving the vehicle uphill (increased engine load) will help maintain the driving conditions required for this test.
4. If DTC is detected, go to [DTC P0744 A/T TCC S/V Function (Lock-Up)].

WITH GST
Follow the procedure "WITH SDT".

Diagnosis Procedure

Steps 1-4: