Scan Tool Data Values

If you have completed the On-Board Diagnostic (OBD) system check, if the diagnostics are functioning properly and if no DTCs display, you may use the Typical Scan Values in the table below for comparison. These typical values are an average on display values recorded from normally operating vehicles. They represent the display from a normally functioning system.
You should never use a scan tool that displays faulty data. The condition should be reported to the manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts.
Only the parameters listed below are used in this manual for diagnosing. If a scan tool displays other parameters, the values are not recommended by General Motors for use in diagnosis.
Scan tests are performed under the following driving conditions:
^ Engine idling
^ Upper radiator hose is hot
^ Closed throttle
^ Transmission is in Park
^ Closed Loop
^ Accessories OFF