What it means
The third transmission fluid temperature sensor signal jumps or drops out intermittently. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
Transmission fluid temperature sensor C sends temperature data to the control module, which checks that the signal remains stable as conditions change. P274E sets when sensor C's reading drops out or jumps intermittently, commonly because its connector or harness loses contact with vibration or movement.
Common causes
Most likely first.
- Sensor connector not fully seated
- Harness chafed against transmission housing
- Connector with intermittent contact under vibration
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and review sensor C's live temperature for sudden jumps or dropouts.
- Inspect the sensor C connector for incomplete seating, moisture, corrosion, or pushed-back pins.
- Check the harness near the transmission housing for chafing, pinching, or heat damage.
- Monitor live temperature while gently moving the connector and harness to locate an intermittent contact.
- If the fault is not reproduced, test sensor C and its wiring for intermittent opens using the wiring diagram and manufacturer's specifications.
Common fixes
- Seat and secure sensor C's connector.
- Repair corroded or damaged connector terminals.
- Repair chafed or pinched wiring and secure the harness.
- Replace sensor C if its signal remains intermittent with a sound connector and harness.
Can I keep driving?
Keep driving gentle and avoid towing because intermittent temperature data can cause erratic shifts or limp mode. Stop if the transmission starts slipping or shift behavior becomes unpredictable.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.