Powertrain, generic (extended)

P274A Transmission Fluid Temperature Sensor C Circuit

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

P274A is the general circuit code for a third transmission fluid temperature sensor, labelled C. Few gearboxes carry three fluid sensors, and no manufacturer publicly documents which measuring point C stands for or what limits apply to P274A. CARB obliges the module to detect broken circuits and readings outside the possible span on such inputs. By analogy with the main sensor, the module watches a thermistor fed through a pull-up resistor and stores this code when the circuit fails without stating whether it is shorted or open; makers that split the fault use P274C/P274D. A substitute value from another sensor normally keeps the car drivable, though temperature-dependent adaptation and protection functions may be restricted.

Likely causes

Connector or lead to sensor C damaged or corroded
Sensor C failed electrically
Control module input stage faulty

Symptoms

  • Warning lamp
  • Implausible value for temperature C on the scan tool
  • Restricted adaptation or protection functions

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

trans fluid temp sensor cwiring harness

Related codes

P274BP274CP274DP274EP0710

References: law.cornell.edu, newtonnet.co.uk.