Q: my 04 sentry has the service engine light on.

If your vehicle’s check engine light illuminates, there is a malfunction that should be diagnosed and repaired. If the check engine light is flashing, that means there is a serious fault, such as cylinder misfiring, that requires immediate repair. Misfiring, in particular, has the potential to damage the catalytic converter which can result in additional costly repairs. If the check engine light is "steadily" illuminated (NOT flashing) the seriousness of the malfunction is hard to judge unless and until a Code Scanner is used by the Mechanic to download the specific trouble codes from your car’s computer (PCM or ECU) that have caused the light to illuminate.

Sometimes the check engine light will illuminate if the gas cap is loose. If the rubber seal on the gas cap is intact and the cap is tight, then all other causes of the light illuminating would have to be evaluated in a check engine light diagnostic. During such a diagnostic, a certified mechanic from YourMechanic would use a code scanner to retrieve diagnostic trouble code(s) from your car’s PCM. Using those codes the appropriate individual vehicle components or sub-systems (often a sensor, circuit, and the like) are tested to pinpoint the cause of the fault or the reason why the check engine light has illuminated. Once the faulty part or component is identified, it is explained to your satisfaction and the mechanic will let you know of the cost to repair. If you schedule the recommended diagnostic, the mechanic will resolve this promptly for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.