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.
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 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 | ● Solenoid status Either solid On or OFF ● Voltage of Battery >10V | |
Threshold Value | ● Voltage <3V | |
Diagnostic Time | ● More than 320 ms | |
Fail Safe | ● Locked in 3 rd gear.(Control relay off) |
Solenoid Valve for Pressure Control
- Sensor type : Normal open 3-way
- Operating temperature : -30℃∼130℃
- Frequency : LR, 2ND, UD, OD, RED : 61.27Hz (at the ATF temp. -20℃ above)
DCC : 30.64Hz
※ KM series : 35Hz
- Internal resistance : 2.7~3.4Ω(20℃)
- Surge voltage : 56 V
