P0199 Code: Engine Oil Temperature Sensor Intermittent
The P0199 code means the engine oil temperature sensor signal cuts out or jumps intermittently. The most likely cause is a poor contact in the connector or a damaged wire, more than the sensor.
- Severity
- Medium
- Can I keep driving?
- Yes, but with caution
- Estimated cost
- $30 to $250
- Difficulty
- Medium
- System
- Air and Fuel
- Applies to
- All OBD2 vehicles
On this page
What the P0199 code means
The engine oil temperature sensor sits in the engine block, in the oil pan, in the oil filter housing or built into the oil level or oil pressure sensor. The computer uses it to protect the engine, to adjust variable valve timing control and, on some vehicles, to calculate the oil change interval.
The computer detected that the oil temperature sensor signal disappears or jumps for a moment and then comes back. These brief dropouts are almost never the sensor. They are the typical signature of a poor contact in the connector or of a wire broken inside its insulation that opens the circuit with vibration or heat.
Keep in mind that the P0199 code points to the circuit where the computer saw the problem, not necessarily the part that failed. Check the wiring before you replace the sensor. The diagnosis steps below walk you through the tests one by one.
P0199 code symptoms
- Check engine light on steadily.
- In many cases you notice nothing while driving, just the light.
- The symptoms come and go, often with bumps, rain or when the engine warms up.
- Possible companion codes from the same sensor (low, high or intermittent signal).
Likely causes of the P0199 code
- Poor contact in the connector: loose, backed-out or corroded pins.
- Wire broken inside its insulation, which opens the circuit with vibration.
- Harness rubbing against moving or hot parts.
- Loose shared ground that affects several sensors at once.
- Sensor with an intermittent internal fault. Less common than the causes above.
- Additional check: A low oil level or badly degraded oil can cause real high readings. Check the oil before you blame the sensor.
How to diagnose the P0199 code step by step
- Read the sensor in live data and compare it with what you expect: with a cold engine it should match the coolant and air temperature. Once running, the oil warms up a little more slowly than the coolant and ends up between 90 and 120 °C (194 to 248 °F).
- Inspect the connector. Unplug it, look for green, backed-out or oily pins, and push it back on firmly.
- With the key on and the sensor unplugged, measure the reference at the connector. You should see about 5 V between the signal and ground.
- Jumper test. With the sensor unplugged, the scan tool should show about -40 °C (-40 °F). When you join the two connector pins with a jumper wire, it should jump to more than 120 °C (248 °F). If it does, the wiring is good and the problem is the sensor.
- Measure the sensor resistance and compare it with the technical data below at the current temperature.
- Do a wiggle test. With the engine running, move the harness and the connector while you watch live data. A jump gives away the point of the fault.
- Check the continuity of each wire between the sensor connector and the computer connector with the key off.
How to fix the P0199 code
- Repair or replace connector terminals that do not hold well.
- Replace the damaged section of wire and protect it from rubbing.
- Replace the sensor only if the fault continues with the wiring in perfect condition.
- Use an original-quality or equivalent sensor: cheap generic sensors often have different response curves.
- Clear the codes, drive a full cycle and check in live data that the reading makes sense.
Technical reference data
- NTC thermistor with 2 wires and a 5 V reference (on some engines combined with the oil level sensor).
- Approximate resistance: 2,000 to 3,000 ohms at 20 °C (68 °F) and 150 to 250 ohms at 100 °C (212 °F).
- Normal oil temperature when running: 90 to 120 °C (194 to 248 °F).
- Approximate values: check the manufacturer data for your engine.
Brand-specific notes
Where the sensor lives depends on the engine, so look up its location before you order parts. That matters if you are chasing the P0199 code and the wiring tests out fine.
P0199 on Volkswagen
On many engines the temperature sensor is combined with the oil level sensor under the oil pan, and the whole assembly is replaced.
P0199 on Audi
On many engines the temperature sensor is combined with the oil level sensor under the oil pan, and the whole assembly is replaced.
P0199 on BMW
On many engines the temperature sensor is combined with the oil level sensor under the oil pan, and the whole assembly is replaced.
P0199 on Mercedes
On many engines the temperature sensor is combined with the oil level sensor under the oil pan, and the whole assembly is replaced.
P0199 on GM
The sensor is usually located near the oil filter.
Questions about the P0199 code
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