Scan Tool Data Definitions
Scan Tool Data Definitions
System Voltage High
The scan tool displays ON or OFF. If the coolant heater voltage is greater than 15 volts when the coolant heater is running, the system voltage high will display ON. If the coolant heater voltage is less than 15 volts, the system voltage high will display OFF.
System Voltage Low
The scan tool displays ON or OFF. If the coolant heater voltage is less than 10.2 volts when the coolant heater is running, the system voltage low will display ON. If the coolant heater voltage is greater than 10.2 volts, the system voltage low will display OFF.
ECT
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 engine control module (ECM) 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 ECM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms and internal resistance decreases, the voltage signal decreases and the ECM interprets the lower voltage as a warm engine.
DTC Set This Ignition
The scan tool displays YES or NO. If the DTC is set to current when the coolant heater is requested on the scan tool will display YES.
Blower Motor
The scan tool displays volts when the blower is requested.
Desired Blower Motor
The scan tool displays volts when the blower motor is commanded ON.
Flame Temperature Sensor
The scan tool displays volts when the flame sensor is activated.
Flame Temperature Sensor
The scan tool displays temperature when the flame sensor is activated.
Glow Plug
The scan tool displays % when the glow plug is active.
Fuel Pump PWM
The scan tool displays MS when the fuel pump is operating.
Ignition 1 Signal
The scan tool displays battery voltage with the key ON.
Temperature Sensor
The scan tool displays the temperature of the coolant inside the coolant heater.
Over Temperature Sensor
The scan tool displays the temperature of the coolant inside the coolant heater.