DTC P0195: Engine Oil Temperature Sensor Circuit Malfunction

In the intricate realm of automotive diagnostics, diagnostic trouble codes (DTCs) are crucial road signs, guiding mechanics towards potential issues within a vehicle’s systems. Among these, DTC P0195 takes the spotlight as a significant indicator of problems related to the Engine Oil Temperature Sensor circuit. This comprehensive article delves into the causes, symptoms, inspection procedures, and effective solutions for addressing and resolving DTC P0195.

1. Causes of DTC P0195:

DTC P0195 emerges when the Engine Control Module (ECM) detects a malfunction within the Engine Oil Temperature Sensor circuit. The underlying causes can encompass:

– Faulty Engine Oil Temperature Sensor: A sensor that inaccurately measures oil temperature can lead to incorrect data transmission.

– Wiring and connector issues: Damaged, corroded, or loose wiring and connectors within the sensor circuit can disrupt proper signal transmission.

– ECM communication problems: An ECM malfunction or communication breakdown can result in misinterpretation of oil temperature data.

2. Symptoms of DTC P0195:

Recognizing the symptoms associated with DTC P0195 aids mechanics in accurately diagnosing the issue:

– Altered engine performance: Incorrect oil temperature data can impact engine performance, especially during cold starts.

– Poor fuel efficiency: Erroneous temperature readings can result in varying fuel consumption.

– Illuminated Check Engine Light (CEL): DTC P0195 triggers the CEL to alert the driver of a potential problem.

3. Inspection of DTC P0195:

Thorough inspection techniques are essential for accurate diagnosis:

– OBD-II scan: Utilize an OBD-II scanner to retrieve the DTC and accompanying freeze frame data, providing insight into the conditions that activated the code.

– Visual examination: Inspect the Engine Oil Temperature Sensor, wiring, and connectors for visible signs of damage, contamination, or corrosion.

– Sensor testing: Measure the sensor’s output using a multimeter or scan tool and compare it to manufacturer specifications.

4. Resolving Causes of DTC P0195:

Addressing DTC P0195 involves specific steps tailored to the underlying issue:

– Engine Oil Temperature Sensor replacement: Replace a malfunctioning sensor with a new, high-quality unit that meets manufacturer specifications.

– Wiring and connector repair: Repair or replace damaged wiring and connectors to restore proper signal transmission.

– ECM diagnosis: If an ECM malfunction is suspected, diagnose and rectify the issue through reprogramming or replacement.

5. Clearing DTC P0195:

After successfully addressing the root cause, clear the DTC from the ECM’s memory using an OBD-II scanner. This step confirms the issue’s resolution and prevents the recurrence of the CEL.


DTC P0195, indicative of an Engine Oil Temperature Sensor circuit malfunction, can impact engine performance and fuel efficiency. Through a comprehensive understanding of its causes, recognition of its symptoms, meticulous inspection techniques, and effective solutions, mechanics can accurately diagnose and rectify this issue. Maintaining accurate oil temperature readings remains pivotal for ensuring proper engine lubrication and efficient operation.