Rough Or Incorrect Idle: Aerio
- Faulty spark plugs. See IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES article.
- Faulty ignition coil. See IGNITION CHECKS in BASIC DIAGNOSTIC PROCEDURES article.
- Idle air control system. See B-6: IDLE AIR CONTROL VALVE SYSTEM CHECK under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article.
- Fast idle control system malfunction. See FAST IDLE AIR VALVE under IDLE CONTROL SYSTEM in SYSTEM & COMPONENT TESTING article.
- Faulty Engine Coolant Temperature (ECT) sensor. See ECT sensor related DTCs in appropriate SELF-DIAGNOSTICS article.
- Faulty Throttle Position (TP) sensor. See TP sensor related DTCs in appropriate SELF-DIAGNOSTICS article.
- Faulty Mass Air Flow (MAF) sensor. See MAF sensor related DTCs in appropriate SELF-DIAGNOSTICS article.
- Faulty fuel injector(s). See B-2: FUEL INJECTOR CIRCUIT INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article.
- Fuel pressure out of specification. See FUEL PRESSURE under FUEL SYSTEM in SYSTEM & COMPONENT TESTING article.
- Exhaust Gas Recirculation (EGR) system malfunction. See EGR valve related DTCs in appropriate SELF-DIAGNOSTICS article.
- EVAP system malfunction. See EVAP system related DTCs in appropriate SELF-DIAGNOSTICS article.
- Faulty Positive Crankcase Ventilation (PCV) system. See POSITIVE CRANKCASE VENTILATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article.
- Check for low engine compression. See MECHANICAL INSPECTION in BASIC DIAGNOSTIC PROCEDURES article.
- Engine overheating/overcooling. See engine overheating related DTCs in appropriate SELF-DIAGNOSTICS article.