Engine

P0196 — Engine Oil Temperature Sensor Range/Performance

Severity: medium Drive with care, to a shop

What P0196 means

The engine control module compares the oil temperature sensor signal with a modeled warm-up curve and other temperature sensors. If the reading is out of range, stuck, or changes in a way that makes no sense, it sets P0196. The sensor is a thermistor whose resistance changes with temperature, and the module reads the voltage drop across it.

Symptoms

  • Check Engine light is on
  • Oil temperature gauge reads erratically or implausibly
  • Reduced fuel economy or sluggish performance
  • Limp mode on some vehicles
  • Oil temperature warning message

Possible causes

  1. Failed oil temperature sensor
  2. Damaged, open or corroded wiring or connector
  3. Poor reference voltage or ground in the sensor circuit
  4. Faulty ECM input channel
  5. Actual oil overheating from a lubrication or cooling problem

How to diagnose

  1. Read all codes and freeze frame data, and look for other temperature-related codes
  2. On a cold engine, compare oil temperature with coolant and intake air temperature
  3. Inspect the sensor, connector and harness for oil contamination, damage and corrosion
  4. Check oil level and condition to rule out real overheating
  5. Measure reference voltage and ground at the sensor connector
  6. Measure sensor resistance and compare it with the spec at a known temperature
  7. Test the wiring to the ECM for opens and shorts
  8. If everything checks out, evaluate the ECM and check for software updates

Common fixes

  • Replace the engine oil temperature sensor
  • Repair or replace damaged wiring and connectors
  • Apply an ECM software update or recalibration if available
  • Repair or replace the ECM if an input channel is faulty

Questions and answers

Can I drive with a P0196 code?

For a short time usually yes, provided there is no real overheating and oil pressure is normal. Don't put off diagnosis, because the ECM is running without accurate oil temperature data.

What most often causes P0196?

Most often it is the oil temperature sensor itself or a wiring or connector problem. Check the harness and connector first, then the sensor resistance.

Does P0196 mean I need a new ECM?

Very rarely. Rule out the sensor, wiring, reference voltage and ground first. The ECM is only suspect once everything else is verified.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.