Powertrain Diagnostic System Check

After performing procedures in PRELIMINARY INSPECTION & ADJUSTMENTS, BASIC FUEL SYSTEM CHECKS and BASIC IGNITION SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article, this is the starting point for utilizing the self-diagnostic system for determining computer-related problems. After performing necessary tests as described in the system check, if no codes are indicated and driveability problems still exist, see appropriate TROUBLE SHOOTING - NO CODES article and SCAN TOOL .

CAUTION: DO NOT perform diagnostic system check if there is not a driveability concern, unless another procedure directs you to this diagnostic procedure. Check for applicable Technical Service Bulletins (TSB) before proceeding. Unless a diagnostic procedure instructs you, DO NOT clear DTCs. Ensure battery is fully charged before proceeding.

NOTE: DO NOT turn ignition off during the following procedure unless instructed to do so.

Connect scan tool. Turn ignition on, with engine off. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST A: SCAN TOOL DOES NOT POWER UP under SYSTEM TESTS in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
If scan tool displays PCM data, go to next step. If scan tool does not display PCM data, go to TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start or starts and then stalls, go to NO-START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Select DTC display function for Powertrain Control Module (PCM), Vehicle Theft Deterrent (VTD) Instrument Panel (IP) cluster, Electronic Brake Control Module (EBCM) and Heating, Ventilation and Air Conditioning (HVAC) controller. If DTCs are stored in any module, go to next step. If no DTCs are stored in any module, go to step 9.
Using scan tool, select CAPTURE INFO to store the powertrain DTC information. After scan tool captures DTC information, go to next step.
If scan tool does not display any DTCs that begin with "U", go to next step. If scan tool displays any DTCs that begin with "U", go to TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
If scan tool displays DTC P0601, P0602, P0604 or P0606, go to DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683: PCM INTERNAL MALFUNCTION under DIAGNOSTIC TESTS. If scan tool does not display DTC P0601, P0602, P0604 or P0606, go to next step.
If scan tool displays DTC P0562, P0563, P1637, or P1638, go to SELF-DIAGNOSTIC SYSTEM in appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.. If scan tool does not display DTC P0562, P0563, P1637, or P1638, repair any other DTCs that are set. See DIAGNOSTIC TROUBLE CODE DEFINITIONS to identify and repair DTCs set in Powertrain Control Module (PCM).
If driveability concern is with automatic transmission, go to diagnostic system check in appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS. If driveability concern is not with automatic transmission, go to next step.
If concern is with Inspection and Maintenance (I/M) testing, go to INSPECTION/MAINTENANCE (I/M) SYSTEM CHECK . If concern is not with I/M testing, go to next step.
Check for driveability symptoms such as hard to start, surges, lack of power, etc. If driveability symptom is identified, perform appropriate test in appropriate TROUBLE SHOOTING - NO CODES article. If no driveability symptoms are present, diagnostic system check is complete.