P0743
P0743Component Location:
General Description
The PCM/TCM controls the locking and unlocking of the Torque Converter Clutch (or Damper Clutch), to the input shaft of the transmission, by applying hydraulic pressure. The main purpose of T/C clutch control is to save the fuel by decreasing the hydraulic load inside the T/C. The TCM outputs duty pulses to control the Damper Clutch Control Solenoid Valve (DCCSV) and hydraulic pressure is applied to DC according to the DCC duty ratio value. When the duty ratio is high, high pressure is applied and the Damper Clutch is locked. The normal operating range of the Damper Clutch Control duty ratio value is from 30% (unlocked) to 85% (locked).
DTC Description
The PCM/TCM checks the Damper Clutch Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored, (For example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected) the TCM judges that the DCCSV circuit is malfunctioning and sets this code.
DTC Detecting Condition:
Schematic Diagram:
Signal Waveform:
Monitor Scantool Data
1. Connect scantool to data link connector (DLC)
2. Engine "ON".
3. Monitor the "TCC SOL. VALVE" parameter on the scantool
4. Select "D RANGE" and Operate the vehicle
5. Check "TCC SOL. VALVE" parameter value changes while driving
6. Does "TCC SOLENOID DUTY" follow the referance data?
YES - Fault is intermittent caused by poor contact in the sensor's and/or TCM (PCM)'s connector or was repaired and TCM (PCM) memory was not cleared. Throughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or damage.Repair or replace as necessary and go to "Verification Vehicle Repair" procedure
NO - Go to "W/Harness Inspection" procedure
Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repair as necessary and then go to "Verification of Vehicle Repair" procedure
NO - Go to "Signal Circuit Inspection" procedure
Signal Circuit Inspection
1. Disconnect "A/T SOLENOID VALVE" connector.
2. IGNITION "ON", ENGINE "OFF"
3. Measure voltage between terminal "1" of the sensor harness connector and chassis ground.
Specification: Approx. 6 V
4. Is voltage within specifications?
YES - Go to "Component Inspection" procedure
NO
- Check for open or short in harness. Repair as necessary and Go to "Verification Vehicle Repair" procedure
- If signal circuit in harness is OK, Go to "Check PCM/TCM" of the "Component Inspection" procedure.
Component Inspection
Check Solenoid Valve
1. Ignition "OFF".
2. Disconnect "A/T SOLENOID VALVE" connector
3. Measure resistance between terminal "1" and chassis ground.
Specification: Approximately 2.7-3.4 ohms (68 °F or 20 °C)
4. Is resistance within specifications?
YES - Go to "CHECK PCM/TCM" as below
NO - Replace TCC SOLENOID VALVE as necessary and go to "Verification Vehicle Repair" procedure
Check PCM/TCM
5. Connect scantool to data link connector (DLC)
6. Ignition "ON" & Engine "OFF".
7. Select A/T Solenoid valve Actuator test and Operate Actuator test.
8. Can you hear operating sound for using "TCC SOLENOID VALVE" Actuator Testing Function?
YES - Go to "Verification Vehicle Repair" procedure
NO - Replace PCM/TCM as necessary and Go to "Verification Vehicle Repair" procedure
NOTE: ACTUATOR TEST CONDITION
1. IG SWITCH ON
2. TRANSAXLE RANGE SWITCH is normal
3. P RANGE
4. Vehicle Speed 0 km/h
5. Throttle position sensor< 1 V
6. IDLE SWITCH ON
7. ENGINE RPM 0
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Using a scantool, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System performing to specification at this time.