P0711
Transmission Fluid Temperature Sensor Circuit Malfunction
Powertrain Transmission Control Transmission Temperature Monitoring 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

Your transmission's temperature sensor isn't sending the right signal to the engine computer, like a broken thermometer that can't tell if the fluid is hot or cold. The transmission control module can't adjust shift timing and fluid pressure properly without this data.

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Symptoms You May Notice
3 known symptoms for this code
Check engine light illuminated
Transmission shifting harshly or at wrong times
Reduced fuel economy or transmission overheating
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECM monitors resistance changes from the transmission fluid temperature (TFT) sensor to calculate fluid temperature. The sensor should produce a voltage signal that changes predictably as temperature rises or falls. Out-of-range voltage, open circuits, or shorts trigger the P0711 fault.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Sensor Voltage 0.5–4.5V depending on temp range <0.1V or >4.9V (open/short circuit)
Fluid Temperature Logic –40°C to +150°C mapped to sensor signal Signal implausibly jumps or stays fixed; no correlation to engine load
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Transmission fluid and filter
Low or contaminated fluid can cause sensor signal faults; drain, refill, and reset the code to confirm.
2
Transmission Fluid Temperature Sensor
Locate the sensor on the transmission pan or valve body, unplug the connector, and unbolt to swap in a new one.
3
Wiring harness and connector
Inspect the sensor connector and wiring for corrosion, loose pins, or breaks; repair or replace if damaged.