DTC 14 - ECT Sensor Circuit Low (High Temperature Indicated): Notes

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1994 GMC Yukon, 1994 GMC Suburban, 1994 GMC Pickup, 1994 GMC Cab & Chassis, and 1994 GMC C3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Engine Coolant Temperature (ECT) sensor is a thermistor that controls signal voltage to PCM. When engine is cold, sensor resistance is high, and PCM will sense a high signal voltage. As engine warms, sensor resistance becomes less and voltage drops. DTC 14 will set when: engine coolant temperature is greater than 304°F (151°C) for 2 seconds.

PCM will default to a engine coolant temperature of 171°F (77°C).

NOTE: Test numbers refer to numbers on diagnostic chart.

This step determines if DTC 14 is the result of a hard failure or an intermittent condition.
This step determines if the ECT signal circuit is shorted to ground