Section 249 (Engine Control System - PID Values, Pcm Connector Views & Terminal Identification): Introduction
The Parameter Identification (PID) charts contain all the engine related parameters that are available on the scan tool. The list is arranged in alphabetical order. A 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 PID charts only after the Diagnostic System Check - Engine Controls has been completed, no DTCs were noted, and you have determined the on-board diagnostics are functioning properly. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 1.8L VIBE article. Scan tool values from a properly running engine may be used for comparison with the engine you are diagnosing. The Typical Scan Data values represent values that would be seen on a normally running engine. Technical Service Bulletins (TSBs) may also be helpful in correcting a hard to diagnose problem.
If all the PID values are within the typical range and a symptom still exists, diagnosis by symptom may help find the fault. See TROUBLE SHOOTING - NO CODES - 1.8L VIBE article.