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
- ECT Sensor 1:
-
The scan tool displays -40 to +151°C (-40 to +304°F). The engine coolant temperature (ECT) sensor is mounted in the coolant stream. The powertrain control module (PCM) applies 5 volts to the ECT sensor signal circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold and the internal resistance is high, the PCM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms and the internal resistance decreases, the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.
- Fan Control 1 Command:
-
This parameter indicates that the PCM is turning ON the fan 1 relay. When the fan 1 relay is ON, both engine cooling fans operate at LOW speed. The PCM will command the fan 1 relay on when AC is selected. The PCM will command the fan 1 relay on when the coolant temperature reaches 98°C (208°F). Once energized the fan 1 relay remains ON until the coolant temperature drops to below 95°C (203°F) or AC is switched Off.
- Fan Control 2 Command:
-
This parameter indicates that the PCM is turning ON the fan 2 relay. When the fan 2 relay is ON, both engine cooling fans operate at HIGH speed.The PCM will command the fan 2 relay on when AC system pressure is more than 2, 100 kPa. The PCM will command the fan 2 relay on when the coolant temperature reaches 102°C (215°F). Once energized the fan 2 relay remains ON until the coolant temperature drops to below 99°C (210°F) or the AC pressure is below 1, 400 kPa.
- Low Coolant Level, Switch Inputs
-
The scan tool displays YES or NO, determined by the state of the low coolant level switch.
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.