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.
DTC P0843: General Description
Transmission fluid pressure sensor is installed in the hydraulic pressure circuit to the over drive clutch. When hydraulic pressure is supplied to the over drive clutch, the transmission fluid pressure sensor output is above the main regulator valve output pressure. When hydraulic pressure is not supplied to the over drive clutch, the transmission fluid pressure sensor output is low pressure. The signal from transmission fluid pressure sensor is input to the powertrain control module (PCM). The PCM detects the hydraulic pressure supply conditions at the over drive clutch. If transmission fluid pressure sensor signal voltage is a specified value for a set time, the PCM detects a transmission fluid pressure sensor failure and stores a DTC.
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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.