Powertrain, generic · Fuel and air metering

P0195 Engine Oil Temperature Sensor A Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The engine oil temperature sensor A is an NTC thermistor fed with 5 V through a resistor: the hotter the oil, the lower the signal voltage. The engine module uses the oil temperature for variable cam timing (Ford disables it with cold oil or a sensor fault), engine protection and the oil life monitor; many engines have no such sensor and use a calculated oil temperature instead. P0195 is the general circuit fault without telling low from high. With analogue sensors most manufacturers use P0197/P0198 instead. The documented use is Ford's 2023 diesels with a digital SENT oil temperature sensor: P0195 is set when the sensor reports a status or data fault for 5 s, while a complete loss of communication is U0667. The module then uses a substitute value (Saab: 100 °C), and functions relying on oil temperature are restricted.

Likely causes

Connector or harness damaged, corroded or oil-soaked
Sensor faulty internally (electronics fault on SENT sensors)
5 V reference or ground problem in the sensor circuit
Control module or software

Symptoms

  • Check engine light on (depending on manufacturer)
  • Oil temperature display missing or fixed
  • Restricted cam timing, slightly reduced power
  • Oil life calculation less accurate

Repair estimate

DifficultyEasyDIY possible
Parts and labour€40–250
Time0.5–1.5 h

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

Parts involved

engine oil temperature sensorsensor wiring

Related codes

P0196P0197P0198P0199P01B9U0667

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