CHECK ENGINE LIGHT on 2006 Suzuki Forenza

My check engine light has been on and off for couple weeks. Car has also been driving rough occasionally. Got an oil change and was advised my serpentine belt was cracked and that would take care of the problem. The repair was completed and noticed the lite came back on. Do you think the belt was/is the problem?

Asked by for the 2006 Suzuki Forenza
A loose fan belt could theoretically cause low charging system voltage if the vehicle was constantly driven with all electrical loads on, lights, heater blower, heated seats ect.... but in practice highly unlikely scenario.
If the check engine light was/is on a trouble code is stored in the memory of the computer in your car. This code is read by a scan tool a generic scanner will do. What code is or was stored? If it wasn't something to do with low battery voltage fan belt wouldn't be the problem.
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After 10k miles and a "lemon law threat" the throttle body was determined to be the problem on my 06.