AutoDiag

P0713

Transmission Fluid Temperature Sensor "A" Circuit High

Moderate· Fix soonProfessionalPowertrainGeneric, all makes

What it means

The transmission fluid temperature (TFT) sensor signal voltage is above the normal range. The transmission fluid temperature (TFT) sensor tells the transmission computer how hot the fluid is, which changes shift timing and torque converter lock-up. A high signal is usually caused by an open circuit (unplugged, broken wire), a missing ground or a short to voltage.

Is it safe to drive?

Drivable gently. Check the fluid level and condition; avoid towing until fixed.

Symptoms

  • Check engine light on
  • Harsh or delayed shifts
  • Torque converter clutch not locking (higher RPM at cruise)
  • Transmission warning light

Probable causes

Most likely first

  1. 1Sensor unplugged or connector loose
  2. 2Open signal or ground wire (broken, corroded or pulled out of the connector)
  3. 3Failed sensor open internally (it reads extremely cold, often -40°)

How to diagnose it

Work through these in order before buying parts

  1. 1Record the code and its freeze frame data (speed, load, temperature when it set), then clear it and see if it comes back.
  2. 2Inspect the transmission fluid temperature (TFT) sensor connector and wiring (inside the transmission, usually on the valve body wiring harness). Look for corrosion, bent or pushed-back pins, oil contamination and chafed insulation.
  3. 3Watch the transmission fluid temperature (TFT) sensor reading on live data. After a cold soak the fluid temperature should match coolant temperature, and rise smoothly as you drive.
  4. 4Unplug the sensor and measure its resistance; it should drop smoothly as it warms up (compare with the chart in a service manual). With the key on, the ECU side of the connector should show about 5 volts on the signal wire and a good ground on the other.
  5. 5If the wiring checks out, test the sensor itself against the specification in a service manual.
  6. 6Check for technical service bulletins (TSBs) or software updates for your make and model; some codes have known factory fixes.

Common fixes

  • Repair the damaged wiring or connector
  • Replace the transmission fluid temperature (TFT) sensor
  • Clear the code and test drive to confirm the repair

This information is general guidance for all makes. Exact causes, specifications and procedures vary by vehicle, so confirm with your service manual or a qualified mechanic before replacing parts.