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 gears should be selected by various signals sent from sensors and switches, and it actuates shift solenoid valves A, B, C, D, and E to control gear selection.
A grade logic control system has been adopted to control shifting in D. The PCM compares actual driving conditions with programmed driving conditions, based on the input from the accelerator pedal position sensor, the engine coolant temperature sensor, the barometric pressure sensor, the brake pedal position switch signal, the output shaft (countershaft) speed sensor signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descending a slope.
The PCM turns shift solenoid valves A, B, C, D, and E ON and OFF to control gear selection. The combination of commands to shift solenoid valves A, B, C, D, and E are in the following table.
| Position | Gear position | Shift solenoid valves | ||||
|---|---|---|---|---|---|---|
| A | B | C | D | E | ||
| D, D3 | Shifting from N | OFF | ON | ON | OFF | OFF |
| Stays in 1st | ON | ON | ON | OFF | OFF | |
| Shifting gears between 1st and 2nd | OFF | ON | ON | OFF | OFF | |
| Stays in 2nd | OFF | ON | OFF | ON | OFF or ON | |
| Shifting gears between 2nd and 3rd | OFF | ON | ON | ON | OFF or ON | |
| Stays in 3rd | OFF | OFF | ON | OFF | OFF or ON | |
| D | Shifting gears between 3rd and 4th | OFF | OFF | OFF | OFF | OFF or ON |
| Stays in 4th | ON | OFF | OFF | OFF | OFF or ON | |
| Shifting gears between 4th and 5th | ON | OFF | OFF | ON | OFF or ON | |
| Stays in 5th | ON | OFF | ON | ON | OFF or ON | |
| 2 | 2nd gear | OFF | ON | OFF | ON | OFF |
| 1 | 1st gear | ON | ON | ON | OFF | OFF |
| R | Shifting from P and N | OFF | ON | OFF | OFF | ON |
| Stays in reverse | ON | ON | OFF | OFF | ON | |
| Reverse inhibit | OFF | OFF | ON | OFF | OFF | |
| P | Park | OFF | ON | OFF | OFF | ON |
| N | Neutral | OFF | ON | ON | OFF | OFF |
Use the Manual With the Right Hardware
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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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