Powertrain, generic (extended)

P274C Transmission Fluid Temperature Sensor C Circuit Low

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

P274C indicates that the sensor C signal has fallen below the lowest value the module accepts. With the negative-temperature-coefficient thermistors normally used for fluid temperature, a low voltage corresponds to very hot fluid, so the usual culprit is a signal lead touching ground or a sensor with an internal short; real heat rarely drives the reading that far. No manufacturer publishes P274C with a threshold. As orientation, Ford's 2012 strategy flags its main sensor below 0.05 V held for 5 to 12 s. Note that some makers, such as Mitsubishi on sensor B, define low by the computed temperature instead, which reverses the meaning. The module then discards C and works with a replacement value.

Likely causes

Signal lead of sensor C shorted to ground
Internal short in sensor C
Control module input faulty

Symptoms

  • Warning lamp
  • Temperature C shows an extremely hot value

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

P274AP274BP274DP274EP274FP0712

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