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-5: 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 ECT sensor. See ECT sensor related DTCs in appropriate SELF DIAGNOSTICS article.
- Faulty TP sensor. See TP sensor related DTCs in appropriate SELF DIAGNOSTICS article.
- Faulty MAF sensor. See MAF sensor related DTCs in appropriate SELF DIAGNOSTICS article.
- Faulty fuel injector(s). See B-1: 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.
- 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 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. See engine overheating related DTCs in appropriate SELF DIAGNOSTICS article.