Code P0117, Coolant Temp Sensor Low Temp Indicated: Notes

WARNING: This page is about a different car, the 1994 Oldsmobile Ninety-Eight and 1994 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.

ECT sensor uses a thermistor to control signal voltage to PCM. PCM applies and monitors a 5 volts to ECT sensor. When engine coolant is cold, sensor (thermistor) resistance is high and PCM will sense a high signal voltage. As engine coolant warms up, sensor resistance becomes less and PCM voltage drops. With Code P0117 set, PCM will turn cooling fans on and use a default engine coolant temperature value based on run time. PCM will illuminate Malfunction Indicator Light (MIL).

NOTE: Test numbers refer to numbers on diagnostic chart.

Code 14 reference applies to 5.7L "Y" body only. This step determines if conditions necessary to set Code P0117 exist.
Determines if circuit is shorted to ground.