Engine Oil Temperature Sensor
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
The engine oil temperature (EOT) sensor is a thermistor whose resistance decreases as engine oil temperature increases. The EOT signal is used by the PCM to calculate fuel quantity, injection timing and glow plug operation.
At low ambient air temperatures and oil temperature below 70°C (158°F), low idle is increased to maintain stable idle quality. Fuel quantity and timing is controlled throughout the total operating range to provide adequate torque and power.
An EOT signal detected out of range, high or low, by the PCM will cause the PCM to substitute a temperature based on ECT to be used for operating purposes.