Engine Oil Temperature Sensor Malfunction
The P0195 code indicates a malfunction in the engine oil temperature (EOT) sensor circuit. The Engine Control Module (ECM) monitors the oil temperature to optimize engine performance and protect against overheating. When the sensor signal is out of expected range or missing, the ECM sets this code. Common causes include a faulty EOT sensor, wiring issues, or a short circuit. This can lead to incorrect fuel delivery, reduced fuel economy, and potential engine damage if ignored.
1. Most Common Causes
- Faulty engine oil temperature (EOT) sensor (internal open or short circuit)
- Damaged EOT sensor wiring or connectors (short to ground, short to power, or open circuit)
- Corroded, loose, or bent pins in the sensor connector
- Extremely low or no engine oil level
- Internal PCM failure (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation
- Engine overheating
- Oil temperature gauge reading incorrectly
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the EOT sensor and wiring for damage or corrosion.
Step 3: Test sensor resistance with a multimeter; compare to manufacturer specs.
Step 4: Check for voltage and ground at the sensor connector.
Step 5: If sensor and wiring are good, test ECM output; replace ECM if necessary.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a faulty oil temperature sensor can lead to incorrect engine management, reduced fuel economy, and potential engine damage from overheating.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the vehicle and shop rates. The sensor itself is usually inexpensive.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.