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.
Shift Control
The PCM instantly determines which gear should be selected by various inputs from sensors and switches, and it actuates the solenoid valves to control gear selection.
Shift solenoid valve:
Shift solenoid valves A, B, and C switch to the hydraulic pressure supply circuit to the clutch. Shift solenoid valves A, B, and C are normally closed (ON-OPEN/OFF-CLOSE); the normally closed solenoid valve port opens to allow ATF to pass through when the PCM turns it ON, and the port closes, blocking fluid flow when turned OFF.
A/T clutch pressure control solenoid valve:
A/T clutch pressure control solenoid valves A, B, C, and D apply hydraulic pressure to each clutch via the hydraulic valve body circuit. A/T clutch pressure control solenoid valve D supplies hydraulic pressure to the torque converter clutch. A/T clutch pressure control solenoid valves A, B, C, and D are normally closed (ON-OPEN/OFF-CLOSE); the normally closed solenoid valve port opens to allow ATF to pass through when the PCM turns it ON, and the port closes, blocking fluid flow when turned OFF. These solenoid valves are controlled by current and are duty controlled depending on the vehicle speed and the throttle position.
Line pressure solenoid valve:
Line pressure solenoid valve A controls the hydraulic pressure in the hydraulic control system valve bodies of the automatic transmission. Line pressure solenoid valve A is normally closed (ON-OPEN/OFF-CLOSE); the normally closed solenoid valve port opens to allow ATF to pass through when the PCM turns it ON, and the port closes, blocking fluid flow when turned OFF.
The combination of driving signals to solenoid valves for each gear is in the following table.
| Shift Lever Position | P | R | N | D, S | |||||
|---|---|---|---|---|---|---|---|---|---|
| 1st | 2nd | 3rd | 4th | 5th | 6th | ||||
| Shift solenoid valve A | ON | OFF | ON | ON | ON | OFF | OFF | OFF | OFF |
| Shift solenoid valve B | OFF | OFF | OFF | ON | ON | ON | ON or OFF | ON or OFF | OFF |
| Shift solenoid valve C | ON | ON | OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF |
| Line pressure solenoid valve A | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF |
| A/T clutch pressure control solenoid valve A | OFF | OFF | OFF | OFF | ON | OFF | OFF | ON | OFF |
| A/T clutch pressure control solenoid valve B | OFF | OFF | OFF | OFF | OFF | ON | OFF | OFF | ON |
| A/T clutch pressure control solenoid valve C | OFF | OFF | OFF | OFF | OFF | OFF | ON | OFF | OFF |
| A/T clutch pressure control solenoid valve D | OFF | ON | OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF | ON or OFF |
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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