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 ), 2-4 ( 2-4 Brake ), UD ( Under Drive Clutch ), OD ( Over Drive Clutch ), REV ( Reverse Clutch ).
The PCM/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 PCM/TCM judges that Under Drive Clutch contorl solenoid circuit is malfunctioning and sets this code.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Check voltage range |
•
Open or short in circuit
•
Faulty UD SOLENOID VALVE
•
Faulty PCM/TCM |
Enable Conditions |
•
16V > Actuator(TCU) power supply voltage >10V | |
Threshold Value |
•
Circuit open or short to ground | |
Diagnostic Time |
•
More than 1sec | |
Fail Safe |
•
Locked in 3 rd gear. |
Solenoid Valve for Pressure Control
Sensor type : Normal open 3-way
Operating temperature : -30℃∼130℃
Frequency :PCSV-A,B,C,D :50Hz (at the ATF temp. -20℃ above)
VFS : 400~1000
※ KM series : 35Hz
Internal resistance : 3.5 ± 0.2 Ω(20℃)
Surge voltage : 56 V
Fig 1) Wave form of "ON/OFF(SCSV-A)" in 1st,3rd,4th gear
Fig 2) Wave form of "ON/OFF(SCSV-A)" in 2nd gear
