Engine Control Module Scan Tool Information (LLU): Notes

The engine control module (ECM) scan tool data list contains all engine related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

Use the Engine Scan Tool Data List only after the following is determined:

DIAGNOSTIC SYSTEM CHECK - VEHICLE is completed.
No diagnostic trouble codes (DTCs).
On-board diagnostics are functioning properly.

The scan tool values from a properly running engine may be used for comparison with the engine you are diagnosing. The engine scan tool data list represents values that may be seen on a normally running engine.

NOTE: A scan tool that displays faulty data should not be used. The scan tool concern should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service manual for use in diagnosis. If all values are within the typical range described below, refer to SYMPTOMS - ENGINE CONTROLS for engine diagnosis.