P0755
P0755Component Location:
General Description
The Automatic Transmission changes the gear position of the transmission utilizing a combination of Clutches and Brakes, which are controlled by solenoid valves. The HIVEC Automatic Transmission consists of a: LR (Low and Reverse Brake), 2ND (2nd Brake), UD (Under Drive Clutch), OD (Over Drive Clutch), REV (Reverse Clutch), and RED (Reduction Brake, only for 5 speed transmissions). The UD Clutch is engaged in the 1st gear, 2nd gear and 3rd gear positions.
DTC Description
The TCM checks the Under Drive 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 Under Drive Clutch control solenoid circuit is malfunctioning and sets this code.
DTC Detecting Condition:
Specification
Solenoid Valve for Pressure Control
- Sensor type : Normal open 3-way
- Operating temperature : -22 - 266 °F (-30 °C - 130 °C)
- Frequency : LR, 2ND, UD, OD, RED : 61.27 Hz (at the ATF temp. -20 °C above)
DCC : 30.64 Hz
- KM series : 35 Hz
- Internal resistance : 2.7 - 3.4 ohms (20 °C)
- Surge voltage : 56 V
Schematic Diagram:
Monitor Scantool Data
1. Connect scantool to data link connector (DLC)
2. Engine "ON".
3. Monitor the "UD SOL. VALVE" parameter on the scantool
4. Shift gear position "1st" gear to "4th" gear.
Specification : P/N --> 100%, D --> 0.0%
5. Does "UD SOLENOID DUTY" follow the referance data?
YES
a. 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
a. 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
a. Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
a. Go to "Power Circuit Inspection" procedure
Power Supply Circuit Inspection
1. Disconnect "A/T SOLENOID VALVE" connector.
2. Measure voltage between terminal "5" of the sensor harness connector and chassis ground.
3. Turn ignition switch OFF --> ON
Specification : 12 V is measured only for approx. 0.5 sec
4. Is voltage within specifications?
YES
a. Go to "Signal Circuit Inspection" procedure
NO
a. Check that A/T - 20 A Fuse in engine room junction is installed or not blown.
b. Check for open in harness. Repair as necessary and Go to "Verification Vehicle Repair" procedure
Signal Circuit Inspection
Check Signal Circuit Open Inspection
1. Ignition "OFF"
2. Disconnect "A/T SOLENOID VALVE" connector and "PCM/TCM" connector
3. Measure resistance between terminal "3" of the ATM SOLENOID VALVE harness connector and terminal "48" of the PCM/TCM harness connector
Specification : approx. 0 ohm
4. Is resistance within specifications?
YES
a. Go to "Check Signal Circuit Short Inspection" procedure
NO
a. Check for open in harness. Repair as necessary and Go to "Verification Vehicle Repair" procedure
Check Signal Circuit Short Inspection
5. Ignition "OFF".
6. Disconnect "A/T SOLENOID VALVE" connector and "PCM/TCM" connector
7. Measure resistance between terminal "3" of the ATM SOLENOID VALVE harness and chassis ground.
Specification : Infinite
8. Is resistance within specifications?
YES
a. Go to "Component Inspection" procedure
NO
a. Check for short to ground in harness. Repair as necessary and Go to "Verification of Vehicle Repair" procedure
Component Inspection
Check Solenoid Valve
1. Ignition "OFF"
2. Disconnect "A/T SOLENOID VALVE" connector
3. Measure resistance between terminal "3" and terminal "5" of the ATM SOLENOID VALVE harness connector
Specification : Approximately 2.7 - 3.4 ohms (20 °C)
4. Is resistance within specifications?
YES
a. Go to "CHECK PCM/TCM" as below
NO
a. Replace UD 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 UD SOLENOID VALVE Actuator Testing Function?
YES
a. Go to "Verification Vehicle Repair" procedure
NO
a. Replace PCM/TCM as necessary and Go to "Verification Vehicle Repair" procedure
CAUTION: 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
a. Go to the applicable troubleshooting procedure.
NO
a. System performing to specification at this time.