P0744

P0744 TORQUE CONVERTER





Description
This malfunction is detected when the A/T does not lock-up. 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.




CONSULT-III Reference Value in Data Monitor Mode









On Board Diagnosis Logic
- This is an OBD-II self-diagnostic item.
- Diagnostic trouble code "P0744" with CONSULT-III or 3rd judgment flicker without CONSULT-III 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 CONSULT-III
1. Start engine.
2. Select "DATA MONITOR" mode for "TRANSMISSION" with CONSULT-III.
3. Drive vehicle and maintain the following conditions for at least 30 consecutive seconds.
ACCEL 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 SEE Diagnosis Procedure.

WITH GST
Follow the procedure "WITH CONSULT-III".




Diagnosis Procedure
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch ON.
2. Select "MAIN SIGNALS" in "DATA MONITOR" mode for "TRANSMISSION" with CONSULT-III.
3. Start the engine.
4. Read out the value of "TCC SOLENOID" while driving.
OK or NG
OK - GO TO 4.
NG - GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Main Power Supply And Ground Circuit.
OK or NG
OK - GO TO 3.
NG - Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following.
- The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK - Replace the control valve with TCM. Service and Repair.
NG - Repair or replace damaged parts.
4.CHECK DTC
Perform "DTC Confirmation Procedure".
- SEE DTC Confirmation Procedure.
OK or NG
OK - INSPECTION END
NG - GO TO 2.