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SensorsSeverity Low: usually safe to drive

P0198Engine Oil Temperature Sensor "A" High

What it means

The engine oil temperature sensor signal voltage is too high. For this type of sensor that means the ECU sees an impossibly low temperature (about −40 °C), usually because the circuit is open. The ECU uses oil temperature for engine protection, variable valve timing and service interval calculations.

Symptoms

  • Check engine light
  • Possibly reduced power or the wrong oil temperature shown

Common causes

  • Open signal or ground wire
  • Unplugged or corroded connector
  • Open circuit inside the sensor

What to check first

  1. Live data shows about −40 °C
  2. Bridge the connector terminals with a jumper: the reading should jump to a very high value
  3. Measure the sensor resistance (OL means it is open)
Can I drive with P0198? Usually yes. P0198 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0198: questions and answers

What does P0198 mean?

P0198: Engine Oil Temperature Sensor "A" High. The engine oil temperature sensor signal voltage is too high. For this type of sensor that means the ECU sees an impossibly low temperature (about −40 °C), usually because the circuit is open. The ECU uses oil temperature for engine protection, variable valve timing and service interval calculations.

What are the symptoms of P0198?

Check engine light. Possibly reduced power or the wrong oil temperature shown.

What causes P0198?

Open signal or ground wire. Unplugged or corroded connector. Open circuit inside the sensor.

How do you diagnose P0198?

1. Live data shows about −40 °C 2. Bridge the connector terminals with a jumper: the reading should jump to a very high value 3. Measure the sensor resistance (OL means it is open)

Can I drive with P0198?

Usually yes. P0198 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.