Powertrain Diagnostic System Check

NOTE: Tech 2 scan tool is required to perform powertrain diagnostic system check.

Powertrain diagnostic system check determines:

If Malfunction Indicator Light (MIL) operates.
If ECM is operating and can recognize a fault.
If any DTCs are stored.

This is the starting point for utilizing the self-diagnostic system for determining computer-related problems. After performing necessary tests as described in the powertrain diagnostic system check, if no codes are indicated and driveability problems still exist, see appropriate TROUBLE SHOOTING - NO CODES article and SCAN TOOL USAGE .

Check if MIL is illuminated with engine running. Check for driveability concerns. Also, check for faulty computer-controlled components. If a problem is found, go to next step. If no problems are found, system is okay.
Turn ignition off. Connect scan tool. Turn ignition on, with engine off. If scan tool displays ECM data, go to next step. If scan tool does not display ECM data, see SCAN TOOL DOES NOT COMMUNICATE WITH KEYWORD DATA LINE in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
Attempt to crank engine. If engine cranks, go to next step. If engine does not crank, diagnose starting and/or charging system.
Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts and stalls, go to NO START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Check for any applicable Technical Service Bulletins (TSBs). Perform repairs as necessary. If no applicable bulletins are found, go to next step.
Using scan tool, check for DTCs. If DTCs are present, go to next step. If no DTCs are present, go to step 8 .
Using scan tool, record any FREEZE FRAME and non-FREEZE FRAME information. Identify DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . After identification, diagnose DTCs. See DIAGNOSTIC TESTS .
With engine running, compare actual scan tool data with typical scan tool data values. If values are within limits, see appropriate TROUBLE SHOOTING - NO CODES article. If values are not within limits, see appropriate SYSTEM & COMPONENT TESTING article.