P1116 CADILLAC Possible Causes
- Low engine coolant level
- Faulty Engine Coolant Temperature (ECT) sensor
- Engine Coolant Temperature (ECT) sensor harness is open or shorted
- Poor electrical connection in the Engine Coolant Temperature (ECT) sensor circuit
- Faulty engine coolant thermostat
How to Fix P1116 CADILLAC Code?
Start by checking the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
Engine light on (or service engine soon warning light)
P1116 CADILLAC Meaning
The Engine Coolant Temperature (ECT) sensor contains a semiconductor device that changes resistance based on temperature (a thermistor). The ECT sensor is mounted in the left bank cylinder head near the front of the engine. The ECT sensor has a signal circuit and a ground circuit. The Powertrain Control Module (PCM) applies a voltage (approximately 5.0 volts) to the sensor signal circuit. The PCM monitors changes in this voltage caused by changes in the sensor’s resistance to determine the engine coolant temperature.
When the engine coolant is cold, the sensor resistance (thermistor) is high and the PCM signal voltage is only slightly lowered across the sensor to ground. The PCM detects a high signal voltage (low temperature). When the engine coolant is hot, the sensor resistance is low and the signal voltage is lowered further. This causes the PCM to detect a low signal voltage (high temperature).