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OBD-II Code

P0199

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$80–$550

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

P0199 is the intermittent version of P0195/P0197/P0198 — the ECU saw the engine oil temperature sensor signal glitch, drop out, or spike momentarily before recovering, and stored the code without committing to a hard high or low designation.

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

  1. Note every code that is set, not just this one.

    Codes that appear together usually narrow the cause faster than any one of them read alone.

  2. Read the freeze frame — the conditions the fault was recorded under.

    Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.

  3. Confirm the fault is current rather than history.

    Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.

  4. Then follow the diagnostic notes further down this page, in the order they are written.

    They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

  • Check engine light
Read the full diagnostic procedureP0199 is the intermittent version of P0195/P0197/P0198 — the ECU saw the engine oil temperature sensor signal glitch, drop out, or spike momentarily…

P0199 is the intermittent version of P0195/P0197/P0198 — the ECU saw the engine oil temperature sensor signal glitch, drop out, or spike momentarily before recovering, and stored the code without committing to a hard high or low designation. Intermittent codes on a sensor that reports correctly when you have it on the scanner are the diagnostic equivalent of chasing a ghost.

Cheapest first

  1. wiggle-test the sensor connector and the harness branch between the sensor and the ECM while watching EOT voltage live data — any signal jump during the wiggle nails the fault to that point.
  2. Inspect the connector for green corrosion, oil seepage (common when the EOT shares a location with the oil filter housing), and back-out pins.
  3. Voltage-drop test the sensor ground from the connector back to battery negative — over 0.1V indicates a degraded ground that intermittently floats the signal.
  4. Heat-cycle the engine and watch for the glitch to appear at a specific oil temp; thermal-expansion-related faults are common where the harness routes near exhaust manifolds.
  5. Use a graphing scan tool or Pico scope to capture the glitch — a stable trace with sharp dropouts during throttle transients points to a loose connector pin; a noisy trace with constant ripple points to a sensor thermistor going bad internally.
  6. The expensive misdiagnosis: replacing the sensor three times because the real fault was a hairline crack in the connector body that only opens up under thermal expansion at 200°F.
Vehicle-specific patterns2011-2019 Ford 6.7L Power Stroke sees P0199 from harness chafe and intermittent connector failure on the EOT sensor circuit, often after engine bay w…
  • 2011-2019Ford 6.7L Power Stroke sees P0199 from harness chafe and intermittent connector failure on the EOT sensor circuit, often after engine bay washes or fluid leaks compromise the connector seal.
  • 2010-2016BMW N20 / N55 inline-6 throws P0199 from the well-known oil-filter-housing-gasket leak that intermittently saturates the EOT connector with oil and degrades the signal contact.
  • 2014-2019GM Duramax L5P / 6.2L direct-injection truck engines sets P0199 from EOT harness rub against the valve-cover bracket or the heat shield on the driver-side exhaust manifold.
  • 2008-2017VW / Audi 2.0T TSI sees P0199 from the oil-temp sensor integrated into the oil cooler assembly developing intermittent thermistor faults around 100k miles; replacement of the integrated sensor module clears it.

Estimated repair$80 to $550.

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