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.
Pattern Select Switch Power Mode Circuit: Description
The ECM memory contains the programs for the normal and power shift patterns and lock-up pattern. By following the programs corresponding to the signals from the No. 1 pattern select switch assembly, the park/neutral position switch and other various sensors, the ECM switches the shift solenoid valves on and off, and controls the transmission gear change and the lock-up clutch operation.
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.