Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Scan Tool Data Definitions
- Coolant Temperature
-
The scan tool displays -40° C to +151° C (-40° F to +304° F). This data is the coolant temperature the Instrument Cluster is attempting to display on the coolant temperature gage.
- ECT
-
The scan tool displays -40° C to +151° C (-40° F to +304° F). The Engine Coolant Temperature (ECT) sensor is mounted in the coolant stream. The PCM applies 5 volts to the ECT sensor circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold (internal resistance high), the PCM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms (internal resistance decreases), the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.
- FC Relay 1 Command
-
The scan tool displays On or Off. This parameter indicates the state of the driver circuit for this device.
- FC Relay 2 and 3 Command
-
The scan tool displays On or Off. This parameter indicates the state of the driver circuit for this device.
- Coolant Level Input
-
The scan tool displays OK or Low. If the ground circuit opens, the scan tool will display Low.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.