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.
Transmission Control Switch (TCS), Transmission Control Indicator Lamp (TCIL)
The TCS is a momentary control switch. When the switch is pressed, a signal is sent to the powertrain control module (PCM) to allow automatic shifts from 1st through 6th gears or 1st through 5th gears only. The PCM energizes the transmission control indicator lamp (TCIL) when the switch is OFF. The TCIL light ON indicates that the overdrive cancel mode is activated. The TCIL light FLASHING indicates monitored sensors, solenoids or other transmission components have failed.
To return to the overdrive mode press the TCIL switch. The (D) OFF indicator light will be illuminated. Each time the vehicle is started, the transmission will automatically return to the overdrive mode. Each time the vehicle is shut OFF and restarted, the TCIL switch will need to be pressed to cancel the overdrive mode if it is not desired.
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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.