Test Notes

EOT Sensor And Related Components:

SIGNAL FUNCTIONS
The Engine Oil Temperature (EOT) sensor is a thermistor type sensor that has a variable resistance that changes when exposed to different temperatures. When interfaced with the Powertrain Control Module (PCM), it produces a 0 to 5 volt analog signal that will deduce temperature.

Cranking Fuel Quantity/Timing Control - The EOT sensor signal is used to determine the timing and quantity of fuel required to optimize starting over all temperature conditions.

Idle Speed - At oil temperatures below 70°C (158°F) low idle is incrementally increased to a maximum of 950 rpm.

Temperature Compensation - Fuel quantity and timing is controlled throughout the total operating range to ensure adequate torque and power is available.

Glow Plug Control - The glow plug relay and lamp ON time are controlled by engine oil temperature.






DETECTION/MANAGEMENT
An EOT sensor signal that is detected out of range (high or low) by the PCM will cause the PCM to ignore the EOT sensor signal and assume an engine oil temperature of -34°C (-29°F) for starting and a temperature of 100°C (212°F) for engine-running conditions. The CHECK ENGINE light will also be illuminated as long as the condition exists.





Connector Checks To Ground (B-)
Check with sensor connector disconnected and ignition key and all accessories OFF.





Connector Voltage Checks
Check with sensor disconnected and ignition key ON.





Harness Resistance Checks
Check with Breakout Box installed on harness only.

NOTE: After removing connectors, always check for damaged pins, corrosion, loose terminals, etc..

EOT Sensor Temperature/Voltage Chart:

DTC DESCRIPTION

Circuit Faults:
0197 = EOT sensor circuit low input.
0198 = EOT sensor circuit high input.

System Faults:
0196 = Engine oil temperature less than 74°C (165°F) or above 116°C (240°F) during Key On Engine Running (KOER) Cylinder Contribution Self Test (self test access denied).