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 - 3.1L CENTURY, GRAND PRIX & MALIBU 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.
Note. Do not use a scan tool that displays faulty data. The scan tool concern should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and in unnecessary parts replacement.
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 - 3.1L CENTURY, GRAND PRIX & MALIBU article.
POWERTRAIN CONTROL MODULE LOCATION
The PCM is located on the left side of engine compartment in air cleaner assembly.
Scheme 1
Scheme 2
Scheme 3
SCAN TOOL DATA LIST DEFINITIONS
| CAUTION | When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. |
Note. See appropriate PID VALUE chart for specific PID application.
3.1L
The column labeled Data List indicates where a parameter is located on the scan tool. Review the scan tool operating manual for the exact locations of the data lists. The following is a description of each term listed.
- Engine Data 1 Contains general informations regarding fuel delivery, IAC position, HO2S1, HO2S2, and other basic engine operating conditions.
- Engine Data 2 Contains general information regarding ECT, IAT, MAF, MAP, and other basic engine operating conditions.
- EVAP Data Contains information specific to the Evaporative Emissions (EVAP) control system. Also displays parameters required to verify proper EVAP system operation.
- Fuel Trim Data Contains specific information specific to the Fuel Trim operation.
- Misfire Data Contains information regarding misfire diagnostics and parameters required to verify proper operation with regard to misfire.
- Output Driver Data Contains information specific to output driver circuits. This data monitors circuit status, and circuit history.
3.8L
The column labeled Data List indicates where a parameter is located on the scan tool. Review the scan tool operating manual for the exact locations of the data lists. The following is a description of each term listed.
- Eng 1 Engine Data 1
- Eng 2 Engine Data 2
- EGR EGR Data
- EVAP EVAP Data
- FUEL TRIM Fuel Trim Data
- Misfire Misfire Data
- ODD Output Driver Data
PID VALUE CHARTS
Ensure following conditions are met before comparing scan tool data to typical data value found in appropriate PID value chart
- Engine is idling unless checking a value at a specified RPM.
- Throttle is closed unless checking a value at a specified RPM.
- Vehicle is in Park or Neutral.
- Vehicle is operating in closed loop.
- Vehicle accessories are turned off.
Compare actual PID values on scan tool to PID values found in appropriate PID value chart.
