P0197 1999 Ford F150 Code - Engine Oil Temperature Sensor Circuit Low Input

P0197 indicates that the Engine Oil Temperature (EOT) sensor circuit is reporting a voltage that is lower than the expected range, suggesting a potential issue with the sensor or its wiring.

Common symptoms include poor engine performance, difficulty starting in cold weather, increased fuel consumption, and an illuminated Check Engine Light.

Possible causes include a faulty Engine Oil Temperature sensor, damaged or corroded wiring, a poor electrical connection, or a malfunctioning powertrain control module (PCM).

Start by checking the EOT sensor and its wiring for physical damage or corrosion. Use a multimeter to test the sensor’s resistance and voltage to ensure it’s within specifications.

While the vehicle may still be drivable, ignoring the issue can lead to poor performance and increased engine wear, especially in extreme temperatures.

Repairs may include replacing the faulty EOT sensor, repairing damaged wiring, cleaning corroded connections, or in rare cases, reprogramming or replacing the PCM.

The EOT sensor is typically located near the oil filter or in the engine block, where it can measure the temperature of the oil directly.

Repair costs vary based on the issue, but replacing the EOT sensor typically costs $50 to $150 for the part, plus labor if done by a mechanic.

While a dirty oil filter doesn’t directly cause the code, it can lead to engine issues that may trigger related problems. Always ensure proper oil and filter maintenance.

Clearing the code may temporarily turn off the Check Engine Light, but the underlying issue must be diagnosed and repaired to prevent the code from returning.