Symptom Diagnosis - Engine Controls
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
When battery is disconnected, vehicle computer may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. Go to appropriate COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting the battery.
NOTE:
For exhaust system symptoms, go to DIAGNOSTIC STARTING POINT - ENGINE EXHAUST
.
Symptom checks should not be used unless symptom occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in appropriate BASIC DIAGNOSTIC PROCEDURES and SELF-DIAGNOSTICS articles were performed before diagnosing a symptom. Symptoms available for diagnosis include:
Symptoms available for diagnosis include:
- BACKFIRES
- CUTS OUT, MISSES
- DETONATION/SPARK KNOCK
- DIESELING/RUN-ON
- ENGINE CRANKS BUT DOES NOT RUN - See NO-START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article.
- HESITATION, SAG OR STUMBLE
- LACK OF POWER, SLUGGISH OR SPONGY
- POOR FUEL ECONOMY
- POOR FUEL FILL QUALITY
- ROUGH, UNSTABLE OR INCORRECT IDLE & STALLING
- VEHICLE SURGES OR CHUGGLES