C-4 System Diagnosis
A built-in diagnostic system is likely to activate if a problem occurs in the system, therefore, begin vehicle diagnosis with the DIAGNOSTIC CIRCUIT CHECK chart. If the C-4 system contains a problem, the "CHECK ENGINE" light will come on. The following items should be checked for proper operation prior to C-4 system diagnosis:
- Intake Manifold & Carburetor Vacuum Leaks
- Vacuum Hoses
- Engine Compression
- Ignition System
- Air Intake System
- Early Fuel Evaporation System
- Positive Crankcase Ventilation (PCV) System
- Exhaust Gas Recirculation (EGR) System
NOTE:
See appropriate fuel evaporation, PCV, and EGR system articles in EXHAUST EMISSION SYSTEMS section.