P0199 is a generic OBD-II powertrain fault code that means Engine Oil Temperature Sensor Intermittent. The ECM/PCM has detected an intermittent, unstable, or inconsistent signal from the engine oil temperature sensor circuit.
P0199 may be encountered on applicable vehicles from Volvo, Toyota, Jeep, and Peugeot. The exact sensor location, wiring configuration, electrical specifications, and diagnostic strategy can vary depending on the engine and model year.
Fault Code Description
P0199 = Engine Oil Temperature Sensor Intermittent.
Code type: Generic OBD-II Powertrain Code.
Likely fault location: Engine oil temperature sensor, sensor connector, signal wiring, sensor ground or reference circuit, or in rare cases the ECM/PCM.
The word Intermittent means the ECM/PCM has detected an unstable or temporarily abnormal sensor signal rather than a continuously high or low input.
What Does P0199 Mean?
The engine oil temperature sensor monitors the temperature of the engine oil and sends an electrical signal to the ECM/PCM. The control module can use this information as part of engine-management and temperature-monitoring strategies.
When the sensor signal suddenly changes, disappears, becomes implausible, or repeatedly behaves outside the expected electrical characteristics, the ECM/PCM may store P0199.
Engine Oil Temperature Sensor Location
The exact location depends on the engine design. The sensor may be installed in or near the oil pan, engine block, oil filter housing, oil cooler circuit, or another location where it can accurately measure engine oil temperature.
Always verify the exact location using the vehicle-specific service information before testing or replacing the sensor.
Symptoms of P0199
- Check Engine Light.
- Intermittent engine oil temperature readings.
- Oil temperature PID may suddenly jump or drop.
- Incorrect engine-management calculations.
- Changes in fuel economy.
- Changes in engine performance on some applications.
- Additional temperature-related diagnostic codes.
- The fault may disappear temporarily and return later.
Common Causes of P0199
- Failing engine oil temperature sensor.
- Loose electrical connector.
- Corroded sensor terminals.
- Damaged wiring.
- Broken wire inside the insulation.
- Intermittent open circuit.
- Intermittent short circuit.
- High resistance in the sensor circuit.
- Oil or moisture contamination at the connector.
- Poor sensor ground or reference connection.
- Vibration-related wiring failure.
- Rarely, an ECM/PCM problem.
How to Fix P0199
1. Scan the Vehicle
Use a professional scan tool to confirm P0199 and check for additional temperature-sensor, powertrain, or electrical codes.
2. Check Freeze-Frame Data
Review the engine conditions recorded when the fault occurred, including engine temperature, RPM, vehicle speed, and the available oil-temperature PID.
3. Check OBD Live Data
Monitor the engine oil temperature PID while the engine is cold, during warm-up, and while gently changing engine speed.
An oil-temperature value that suddenly jumps, drops, freezes, or becomes unrealistic can help identify an intermittent sensor or circuit problem.
4. Inspect the Sensor and Connector
Inspect the engine oil temperature sensor and connector for loose terminals, corrosion, oil contamination, damaged locking tabs, or physical damage.
5. Perform a Wiggle Test
With the scan tool displaying live oil-temperature data, gently move the sensor wiring and connector. If the temperature reading changes suddenly while the wiring is moved, an intermittent connection or damaged wire is possible.
6. Test the Wiring and Sensor
Use the manufacturer's wiring diagram to test continuity, resistance, reference voltage, and ground as applicable. Compare the sensor resistance or signal with the manufacturer's specifications at the measured oil temperature.
7. Verify the Repair
After repairing the wiring, connector, or sensor, clear the code and monitor the live data during a complete warm-up and road-test cycle to confirm that the signal remains stable.
P0199 Diagnostic Signal Flow
↓
Engine Oil Temperature Sensor
↓
Sensor Signal / Ground Circuit
↓
ECM / PCM
↓
Oil Temperature Calculation
↓
Engine Management Strategy
P0199 OBD Live Data
Live data is particularly useful for P0199 because the fault is intermittent. Compare the oil-temperature reading with coolant temperature, intake-air temperature, and ambient temperature when the engine is cold.
During warm-up, the oil-temperature reading should change progressively according to the vehicle's operating conditions. Sudden unrealistic changes can indicate an intermittent electrical problem.
P0199 Toyota, Volvo, Jeep and Peugeot
The base definition of P0199 is generic, but the actual diagnostic procedure can differ between manufacturers because the sensor location, wiring configuration, connector design, sensor specifications, and ECM/PCM monitoring strategy may vary by engine.
P0199 Toyota
On applicable Toyota vehicles, monitor the oil-temperature PID and compare its behavior with other available temperature readings during cold start and warm-up.
Inspect the sensor connector and wiring for loose terminals, corrosion, damaged insulation, or intermittent resistance. Use Toyota-specific sensor resistance and voltage specifications for the exact engine.
P0199 Volvo
On applicable Volvo vehicles, check the engine oil temperature reading for sudden or unrealistic changes and compare it with other available temperature PIDs.
Inspect the sensor circuit, connector, and wiring for intermittent signal loss or high resistance. The exact sensor location and specifications depend on the engine.
P0199 Jeep
On applicable Jeep vehicles, use live data to monitor engine oil temperature while inspecting the sensor connector and wiring.
A wiggle test can help reproduce an intermittent fault caused by a loose terminal, damaged wire, or high-resistance connection. Verify the correct Jeep wiring diagram for the specific engine.
P0199 Peugeot
On applicable Peugeot vehicles, check the engine oil temperature signal using the appropriate diagnostic equipment.
Inspect the sensor connector and wiring for corrosion, damaged terminals, poor connections, or wiring faults. Compare resistance and continuity with the specifications for the exact engine.
Across all four manufacturers, the most reliable approach is to confirm the intermittent condition using live data, inspect the sensor and connector, test the wiring, and verify the sensor against manufacturer specifications before replacing components.
P0199 vs P0196
P0196 indicates an engine oil temperature sensor range/performance problem, while P0199 specifically indicates an intermittent sensor signal.
P0199 vs P0197
P0197 indicates a low input from the engine oil temperature sensor circuit, while P0199 indicates that the signal is intermittent or unstable.
P0199 vs P0198
P0198 indicates a high input from the engine oil temperature sensor circuit. P0199 instead points to an intermittent signal condition.
Is P0199 Serious?
P0199 should be diagnosed rather than ignored. An intermittent sensor signal can affect engine-management calculations and may eventually become a permanent sensor or wiring failure.
If the vehicle also has an oil-pressure warning, overheating, severe engine noise, or major loss of power, stop driving and investigate the underlying problem immediately.
Can I Drive With P0199?
Limited driving may be possible if the engine is operating normally and there are no oil-pressure or overheating warnings. However, an intermittent fault should be diagnosed as soon as possible because the condition can worsen or become permanent.
P0199 Repair Cost
- Electrical diagnosis: approximately $50–$150+.
- Wiring or connector repair: approximately $50–$250+.
- Engine oil temperature sensor: approximately $80–$300+.
- ECM/PCM diagnosis or repair: potentially considerably more.
These are general estimates only. Actual repair costs depend on the vehicle, engine, parts prices, sensor location, and labor rate.
Common Repair Mistakes
- Replacing the sensor without checking the connector.
- Ignoring broken wires hidden inside the insulation.
- Failing to perform a wiggle test.
- Checking the sensor only when the fault is not active.
- Ignoring live-data changes.
- Using the wrong wiring diagram or sensor specifications.
- Replacing the ECM/PCM before verifying the complete sensor circuit.
Related Codes
- P0195 – Engine Oil Temperature Sensor Circuit
- P0196 – Engine Oil Temperature Sensor Range/Performance
- P0197 – Engine Oil Temperature Sensor Low Input
- P0198 – Engine Oil Temperature Sensor High Input
FAQ About P0199
What does P0199 mean?
P0199 means Engine Oil Temperature Sensor Intermittent. The ECM/PCM has detected an unstable or intermittent signal from the engine oil temperature sensor circuit.
How do I fix P0199?
Start by checking freeze-frame and live data. Then inspect the sensor and connector, perform a wiggle test, test the wiring, and verify the sensor according to manufacturer specifications.
What is the most common cause of P0199?
Common possibilities include a failing oil-temperature sensor, loose connector terminals, damaged wiring, intermittent open circuits, or high resistance in the sensor circuit.
Can a loose connector cause P0199?
Yes. A loose or corroded connector can temporarily interrupt the sensor signal and cause the ECM/PCM to detect an intermittent condition.
Can damaged wiring cause P0199?
Yes. Wiring that is broken internally, rubbed against another component, or affected by engine vibration can create an intermittent sensor signal.
What does P0199 mean on Toyota?
On applicable Toyota vehicles, P0199 indicates an intermittent engine oil temperature sensor signal. Check the sensor, connector, and wiring using Toyota-specific specifications.
What does P0199 mean on Volvo?
On applicable Volvo vehicles, P0199 indicates an intermittent engine oil temperature sensor signal. The exact diagnostic procedure depends on the engine and sensor configuration.
What does P0199 mean on Jeep?
On applicable Jeep vehicles, P0199 indicates an intermittent engine oil temperature sensor signal. Live-data monitoring and a wiring inspection can help identify the intermittent fault.
What does P0199 mean on Peugeot?
On applicable Peugeot vehicles, P0199 indicates an intermittent engine oil temperature sensor signal. Inspect the sensor, connector, wiring, and live-data behavior before replacing components.
Is P0199 the same on every vehicle?
The base definition is generic, but the sensor design, location, wiring, monitoring conditions, and diagnostic specifications can differ between Toyota, Volvo, Jeep, Peugeot, and other manufacturers.