P1874: Transmission Automatic Hall Effect Sensor Power Circuit Failure

What does P1874 mean?

P1874 is a diagnostic trouble code indicating "Transmission Automatic Hall Effect Sensor Power Circuit Failure". A sensor in the transmission is reporting abnormal data or has lost communication with the ECU. Sensors can fail due to age, contamination, heat exposure, or wiring issues.

Symptoms you may notice

• Check engine light (MIL) illuminated on dashboard
• Harsh or delayed gear shifts
• Transmission slipping
• Vehicle stuck in one gear (limp mode)
• Intermittent warning lights

Common causes

• Low or degraded transmission fluid
• Worn clutch packs or bands
• Faulty shift solenoid
• Wiring issue to the transmission control module
• Failing torque converter

What should you do?

Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.

Get a diagnosis for YOUR car

Code P1874 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.

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