Faulty engine oil temperature sensor (both sources). Wiring problems, such as loose connections or damaged wires (both sources). Engine cooling system problems, for example an engine that overheats or never warms up properly (OBD-Codes.com). PCM failure (both sources; check everything else first).

Repair a loose connector or damaged wiring at the oil temperature sensor. Replace the engine oil temperature sensor. Fix the underlying cooling system problem if the engine overheats or doesn't warm up (OBD-Codes.com). Repair or replace the PCM only after the sensor, wiring and cooling system check out.

P0195🔧 Engine / engine oil temperature sensorStop and fix promptly

P0195: Engine Oil Temperature Sensor Circuit Malfunction (Meaning, Causes, Fixes)

Q: What does P0195 mean?

P0195 means the engine computer has found a problem in the engine oil temperature sensor circuit. Both OBD-Codes.com and RepairPal list a failed sensor, wiring problems and, rarely, the PCM; OBD-Codes.com also lists cooling system problems. Confirm the engine warms up and holds a normal temperature first, then check the sensor and its wiring. The engine oil temperature (EOT) sensor tells the engine computer (PCM) how hot the oil is. OBD-Codes.com says the PCM uses this signal for things like fuel quantity, injection timing and glow plug operation, and also compares it with the intake air and coolant temperature sensors as a cross-check. EOT sensors are most common on diesels, and OBD-Codes.com names Ford Powerstroke, Chevrolet/GMC Duramax, Dodge, Jeep and Audi among the vehicles that use one. The sensor is a thermistor that gets a 5-volt reference from the PCM; its resistance drops as the oil heats up, so the signal voltage goes down as the oil gets hotter. P0195 is the general circuit code for this sensor: OBD-Codes.com says it sets when the PCM detects a malfunction in the EOT sensor circuit, and RepairPal says it sets when the PCM detects an incorrect signal from the sensor. The more specific codes in the same family are P0196 (range/performance), P0197 (circuit low), P0198 (circuit high) and P0199 (intermittent). The sources differ a little: OBD-Codes.com titles the code 'Engine Oil Temperature Sensor Malfunction' while RepairPal titles it 'Engine Oil Temperature Sensor Circuit', and OBD-Codes.com includes engine cooling system problems among the causes while RepairPal lists only the sensor, the PCM and wiring.

Q: Can I keep driving with P0195?

Stop and fix promptly. Check your temperature gauge before driving. RepairPal rates P0195 Urgent, and OBD-Codes.com calls it moderate to severe, warning that when it sets along with coolant temperature codes it can point to an engine that is overheating. If the gauge reads high, steam is coming from the engine, or you also have coolant temperature codes, pull over and shut the engine off rather than risk engine damage. If the engine warms up and runs at a normal temperature, the fault is more likely the sensor or its wiring, but both sources say to get it fixed soon.

Reviewed 2026-10-25 · Based on 2 cited source(s)

What P0195 means

The engine oil temperature (EOT) sensor tells the engine computer (PCM) how hot the oil is. OBD-Codes.com says the PCM uses this signal for things like fuel quantity, injection timing and glow plug operation, and also compares it with the intake air and coolant temperature sensors as a cross-check. EOT sensors are most common on diesels, and OBD-Codes.com names Ford Powerstroke, Chevrolet/GMC Duramax, Dodge, Jeep and Audi among the vehicles that use one. The sensor is a thermistor that gets a 5-volt reference from the PCM; its resistance drops as the oil heats up, so the signal voltage goes down as the oil gets hotter. P0195 is the general circuit code for this sensor: OBD-Codes.com says it sets when the PCM detects a malfunction in the EOT sensor circuit, and RepairPal says it sets when the PCM detects an incorrect signal from the sensor. The more specific codes in the same family are P0196 (range/performance), P0197 (circuit low), P0198 (circuit high) and P0199 (intermittent). The sources differ a little: OBD-Codes.com titles the code 'Engine Oil Temperature Sensor Malfunction' while RepairPal titles it 'Engine Oil Temperature Sensor Circuit', and OBD-Codes.com includes engine cooling system problems among the causes while RepairPal lists only the sensor, the PCM and wiring.

Severity: can I keep driving?

Stop and fix promptly

Check your temperature gauge before driving. RepairPal rates P0195 Urgent, and OBD-Codes.com calls it moderate to severe, warning that when it sets along with coolant temperature codes it can point to an engine that is overheating. If the gauge reads high, steam is coming from the engine, or you also have coolant temperature codes, pull over and shut the engine off rather than risk engine damage. If the engine warms up and runs at a normal temperature, the fault is more likely the sensor or its wiring, but both sources say to get it fixed soon.

Common symptoms

Check engine light on (OBD-Codes.com; it is the only symptom listed)
If coolant temperature codes are set too, possible overheating (OBD-Codes.com)
RepairPal gives no symptom list for this code

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Faulty engine oil temperature sensor (both sources)
Wiring problems, such as loose connections or damaged wires (both sources)
Engine cooling system problems, for example an engine that overheats or never warms up properly (OBD-Codes.com)
PCM failure (both sources; check everything else first)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Visually inspect the oil temperature sensor and its wiring for loose connectors or damaged wires, repair anything you find, clear the code and see if it comes back (OBD-Codes.com).
Look up technical service bulletins (TSBs) for your year, make, model and engine (OBD-Codes.com).
Watch the dash temperature gauge. OBD-Codes.com says to confirm the engine reaches and holds normal operating temperature, and to fix any overheating or slow warm-up problem before testing further. Coolant temperature codes set at the same time also point to the cooling system.
With a scan tool, watch the engine oil temperature reading. OBD-Codes.com's quick check: unplug the sensor and the reading should drop very low; jumper the two connector terminals and it should jump very high. If it does both, the wiring and PCM can see the input and the sensor is the likely problem.
With the sensor unplugged, measure resistance across its two terminals with a multimeter while the engine warms up. It should decrease smoothly; if the engine warms but resistance doesn't drop, OBD-Codes.com says to replace the sensor. Your service manual's resistance/temperature chart gives exact values.

Typical fixes

Repair a loose connector or damaged wiring at the oil temperature sensor
Replace the engine oil temperature sensor
Fix the underlying cooling system problem if the engine overheats or doesn't warm up (OBD-Codes.com)
Repair or replace the PCM only after the sensor, wiring and cooling system check out

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

OBD-Codes.com's circuit checks: with the ignition on, look for a 5-volt reference at one sensor terminal. If it's missing, check continuity from the sensor reference pin to the PCM (an OL reading means an open circuit), and then whether 5 volts is leaving the PCM. No reference out of the PCM suggests a faulty PCM.
Check the ground side the same way, sensor ground to PCM ground, and then the PCM's own ground to chassis.
Use the manufacturer's diagnostic flow chart; OBD-Codes.com notes that testing varies by vehicle.

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Is P0195 serious?

It can be. RepairPal rates it Urgent and OBD-Codes.com calls it moderate to severe, mainly because it can show up with an engine that is overheating. If your temperature gauge is normal and there are no coolant codes, it's more likely the sensor or wiring, but still get it fixed soon.

How is P0195 different from P0196, P0197 and P0198?

They're all the same sensor. P0195 is the general circuit fault. P0196 means the reading doesn't make sense, and P0197 and P0198 mean the circuit voltage is too low or too high. If more than one of these is set, start with the wiring and connector.

Is P0195 common on Ford diesels?

Google search suggestions for P0195 often mention Ford, and OBD-Codes.com lists the Ford Powerstroke among vehicles with this sensor, but neither source we used gives a model-specific cause. Check for TSBs on your exact vehicle.

Will replacing the sensor fix P0195?

Often, but not always. Both sources list wiring and the PCM, and OBD-Codes.com lists cooling system problems. Do the scan tool unplug-and-jumper check and confirm normal warm-up before buying a sensor.

Sources

Last reviewed 2026-10-25. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.