The Oil Temperature Sensor plays a key role in monitoring the operating temperature of the engine’s motor oil. This sensor provides the ECU with real-time data, which helps manage various engine functions including fuel injection timing, turbo boost control, and fan activation. By ensuring that engine oil stays within optimal temperature ranges, the sensor supports overall engine protection, performance, and efficiency. This is especially important in modern engines with tighter tolerances and advanced emissions systems, where proper oil temperature is essential for safe and efficient operation.
Common causes of Oil Temperature Sensor failure include:
• Internal electrical failure
• Oil contamination or sludge buildup
• Damaged wiring or poor electrical connections
• Sensor exposure to extreme engine heat over time
Symptoms of a failing Oil Temperature Sensor may include:
• Erratic or inaccurate oil temperature readings
• Poor engine performance
• Reduced fuel efficiency
• Illumination of the Check Engine Light
• Engine running hotter or cooler than normal
The following OBD II error codes are the most commonly found with this product type. In an effort to reduce vehicle emissions, the Environmental Protection Agency (EPA) mandated that all vehicles manufactured after 1996 be equipped with OBD II (On-Board Diagnostics 2) technology. OBD II is now the standard in diagnosing vehicle emissions and system faults, and is implemented across all automotive manufacturers. The codes listed for this product type are common instances that may relate to your vehicle and should be used as a guide only. Walker Products will not be held responsible for any use of this information. It is highly suggested that you consult with a professionally trained mechanic prior to any automotive repair, and that you follow all vehicle manufacturer and EPA guidelines for removal, replacement, diagnostics, OBD II code clearing, ECU, and PCM relearn procedures.
o P0196 Engine Oil Temperature Sensor Range/Performance
o P0197 Engine Oil Temperature Sensor Low Input
o P0198 Engine Oil Temperature Sensor High Input
o P0199 Engine Oil Temperature Sensor Intermittent