Powertrain, generic (extended)

P274B Transmission Fluid Temperature Sensor C Circuit Range/Performance

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

P274B means the sensor C signal is within electrical limits but does not fit the other information, for example because it barely changes while the gearbox warms or contradicts the other temperature values. The only public manufacturer reference is Ford bulletin 20-2044: 2020 Super Duty trucks with the 6.7 L diesel, built up to 5 February 2020, could light the MIL with P274B, often together with P203B and P2201, purely through PCM software; the remedy is reprogramming, about 0.6 h of labour. Ford does not say which measuring point C is. On other vehicles a sensor drifting with age, a high-resistance connection or contaminated fluid are more likely. P274A, P274C and P274D cover outright electrical faults.

Likely causes

PCM software (Ford 2020 Super Duty 6.7 L, TSB 20-2044)
Sensor C drifting or slow to respond
Added resistance in connector or lead

Symptoms

  • Malfunction indicator lamp on
  • Temperature C stays nearly constant while driving

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.5–4 h

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

Parts involved

trans fluid temp sensor c

Related codes

P274AP274CP274DP274EP0711

References: static.nhtsa.gov, law.cornell.edu.