P274D is set when the sensor C signal climbs above its highest permitted value. On a thermistor supplied with 5 V via a resistor, that happens when the circuit opens – a broken wire, a corroded or unplugged connector – or when the signal line touches a voltage source; the display would then show fluid colder than any real climate produces. No manufacturer documents P274D publicly. For the main sensor, Ford's 2012 strategy uses above 4.6 V, and GM's 2023 dual-clutch module above 4745 mV for its sump sensor, both as electrical limits rather than temperatures. Until the fault is cleared the transmission may keep a cold-fluid strategy with delayed converter lock-up or more cautious clutch control.
Medium severity. Can I keep driving?Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.
Symptoms
- Warning lamp
- Temperature C shows an extremely cold value
- Late converter lock-up or cautious shifting
Most likely causes
- Open circuit in sensor C lead or connector
- Signal lead shorted to voltage
- Sensor C open internally
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of P274D means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 7: Transmission
- 4D: Specific fault in that system
Frequently asked questions
Can I keep driving with code P274D?
Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.
What causes code P274D?
The most common causes are: open circuit in sensor C lead or connector; signal lead shorted to voltage; sensor C open internally.
Related codes
- P274ATransmission Fluid Temperature Sensor C Circuit
- P274BTransmission Fluid Temperature Sensor C Circuit Range/Performance
- P274CTransmission Fluid Temperature Sensor C Circuit Low
- P274ETransmission Fluid Temperature Sensor C Circuit Intermittent
- P0713Transmission Fluid Temperature Sensor A Circuit High
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.