Symptom Checks

Perform the following:

• Perform Key On Engine Off (KOEO) Self-Test. See step 1) of DIAGNOSTIC SUB-ROUTINES.
• Check power to MAP/BARO sensor. See step 3) of CIRCUIT TEST S in appropriate TESTS W/CODES article in the ENGINE PERFORMANCE section.
• Check ignition system. See IGNITION SYSTEMS in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE section.
• Check fuel delivery system. See FUEL SYSTEM in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE section.
• Check for restricted exhaust system.
• Ensure engine operates at normal operating temperature.
• Check air intake system. Ensure throttle plate and linkages operate properly.
• Check engine mechanical condition. Check compression, intake manifold gasket, camshaft, valve train components, etc.
• Ensure transmission is functioning properly.
• Check for binding/dragging brakes.
• Check EGR system. See EMISSION SYSTEMS & SUB-SYSTEMS in appropriate I - SYS/COMP TESTS article in the ENGINE PERFORMANCE section.
• Ensure A/C turns off during Wide Open Throttle (WOT).
• Check customer driving habits (over RPM/speed limiting function enabled).