Effect on Fuel Injection

Coolant Temperature Sensor:

PURPOSE
Sensor is input device by which EFI ECM monitors engine coolant temperature.

OPERATION
The sensor is a thermistor device whose resistance changes in relation to temperature. Resistance changes are interpreted by the ECM as engine temperature fluctuations. When temperatures are within ECM programmed parameters, air/fuel ratio will be enriched during cold start and warm-up by increasing injector pulse width ("ON" time).

Temperature / resistance relationship is as follows:

TEMP (°F / °C) OHMS

50 / 10 5.9K
68 / 20 2.5K
86 / 30 1.7K
104 / 40 1.2K
122 / 50 840
140 / 60 600
158 / 70 435
176 / 80 325
194 / 90 250
212 / 100 190

LOCATION
Mounted in left thermostat housing.