Operation CHARM: Car repair manuals for everyone.
Home >> Chevrolet >> 2007 >> Express 2500 V8-6.0L >> Repair and Diagnosis >> Engine, Cooling and Exhaust >> Cooling System >> Testing and Inspection >> Scan Tool Testing and Procedures
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Scan Tool Testing and Procedures



Scan Tool Data Definitions

Cooling Fan Command
- The percent of engine cooling fan requested from the ECM.

Desired Fan Speed
- Requested fan speed from the ECM.

ECT Sensor
- 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 and internal resistance is high, the PCM 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 PCM interprets the lower voltage as a warm engine.

Fan Speed
- Actual fan speed.

pro multis · About Operation CHARM