The Automatic Transmission changes the gear position of the transmission utilizing a combination of Clutches and Brakes, which are controlled by solenoid valves. Low coast brake solenoid valve is controlled by the TCM in response to signals sent from the inhibitor switch, vehicle speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be shifted to the optimum position.
The PCM/TCM checks the Shift Control Solenoin Valve E 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 votage detected when high voltage is expected)
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Check voltage range(Open, Short) |
•
Open or short in circuit
•
Faulty pressure switch 2
•
Faulty LC/B solenoid valve
•
Faulty TCM |
Enable Conditions |
•
10V < Actuator Supply Voltage < 16V | |
Threshold Value |
•
Hardware IC check | |
Diagnostic Time |
•
More than 0.2sec | |
Fail Safe |
•
OFF fail : Only LC/B OFF, The others are controlled as usual
•
ON fail : Lock as 4th gear |
Fig 1) LC/B solenoid operation
Fig 2) Signal Waveform at IDLE
Fig 3) Signal Waveform at accelleration
