Powertrain, generic (extended)

P273F Transmission Fluid Temperature Sensor B Over Temperature Condition

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P273F is a condition code, not a wiring fault: sensor B delivers a valid reading, but that reading lies above the overheating limit the calibration allows. No manufacturer publishes P273F or its threshold. The analogous code for sensor A is P0218; Saab's Aisin automatic, for instance, sets it once the fluid stays above 170 °C for over 10 s. Where sensor B measures the oil leaving the cooler, as on GM and Ford dual-clutch units, a high value hints that the cooler itself is no longer removing heat. Typical reactions are a warning message, reduced torque or an altered shift and clutch strategy. Look for towing or track use, low fluid, a blocked cooler or a failed cooler valve before suspecting the sensor.

Likely causes

Sustained high load – towing, track use, long climbs
Fluid cooler clogged or cooler valve not opening
Fluid level low or fluid aged
Sensor B reading too hot while still in range

Symptoms

  • Transmission overheating message
  • Reduced torque or changed shift pattern
  • Burnt-smelling or darkened fluid

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,200
Time0.5–5 h

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

Parts involved

trans fluid temp sensor btransmission fluidcooler

Related codes

P2740P2741P2742P0218P2753

References: law.cornell.edu, saabwisonline.com, fordservicecontent.com.