Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Hyundai Veloster 2.0, Automatic TransFACTORY OEM SERVICE PROCEDURE
TCM Terminal Input/Output Signal
| Pin | Description | Condition | Input/output value | |
|---|---|---|---|---|
| Type | Level | |||
| A1 | Overdrive clutch control solenoid valve (OD/C_VFS) | - | Output | 0V/Battery voltage level |
| 9V < Battery voltage level < 16V | ||||
| A5 | Torque converter control solenoid valve (T/CON_VFS) | - | Output | 0V/Battery voltage level |
| 9V < Battery voltage level < 16V | ||||
| A6 | Line pressure control solenoid valve (LINE_VFS) | - | Output | 0V/Battery voltage level |
| 9V < Battery voltage level < 16V | ||||
| A7 | 26 brake control solenoid valve (26/B_VFS) | - | Output | 0V/Battery voltage level |
| 9V < Battery voltage level < 16V | ||||
| A8 | Inhibitor switch signal "S2" | High | Input | 0V/Battery voltage level |
| Low | 9V < Battery voltage level < 16V | |||
| A9 | Sports mode down switch | Down ON | Input | 0V/Battery voltage level |
| Other | 9V < Battery voltage level < 16V | |||
| A10 | Sports mode up switch | Up ON | Input | 0V/Battery voltage level |
| Other | 9V < Battery voltage level < 16V | |||
| A22 | Underdrive brake control solenoid valve (UD/B_VFS) | - | Output | 0V/Battery voltage level |
| 9V < Battery voltage level < 16V | ||||
| A26 | 35R clutch control solenoid valve (35R/C_VFS) | - | Output | 0V/Battery voltage level |
| 9V < Battery voltage level < 16V | ||||
| A27 | Inhibitor switch signal "S1" | High | Input | 0V/Battery voltage level |
| Low | 9V < Battery voltage level < 16V | |||
| A30 | Sports mode select switch | Sport mode | Input | 0V/Battery voltage level |
| Other | 9V < Battery voltage level < 16V | |||
| A43 | Solenoid power 1 (A1, A5, A26, A48) | Power | 0V/Battery voltage level | |
| 9V < Battery voltage level < 16V | ||||
| A44 | Solenoid power 2 (A6, A7, A22, A47) | Power | 0V/Battery voltage level | |
| 9V < Battery voltage level < 16V | ||||
| A48 | ON/OFF solenoid valve A (SS-A) | High | Output | 0V/Battery voltage level |
| Low | 9V < Battery voltage level < 16V | |||
| A49 | Oil temperature sensor (-) | - | Ground | 0V |
| A70 | Inhibitor switch signal "S3" | High | Input | 0V/Battery voltage level |
| Low | 9V < Battery voltage level < 16V | |||
| A73 | Output speed sensor power | ON | Power | 0V/7.5V |
| OFF | ||||
| A91 | Oil temperature sensor (+) | ON | Input | 0V/3.3V |
| OFF | ||||
| A92 | Output speed sensor signal | High | Input | 0.7V/1.4V |
| Low | ||||
| A93 | Inhibitor switch signal "S4" | High | Input | 0V/Battery voltage level |
| Low | 9V < Battery voltage level < 16V | |||
| A94 | Input speed sensor power | ON | Power | 0V/7.5V |
| OFF | ||||
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.