Q: My Check Engine Light came on 2 days after we replaced our battery

The Check Engine Light may or may not be related to the battery change on any late-model car like this one - even a simple operation like changing a battery is not so simple. There are a number of settings and values in your cars control systems that are retained only by a very small amount of battery power while everything on the car is shut off. Disconnecting the battery for just enough time to replace it can cause the controllers to lose these values and it may take some time to re-learn some of them.

You need to read the codes on the car and if the code is for a throttle position sensor or an improper voltage, it may be because of your battery replacement. Other codes for "hard"failures may be present that have nothing to do with your battery replacement. To be sure, you can erase the codes and see if they re-occur. If the Check Engine Light does not come back, you’re in the clear. If the code is due to something that is unrelated, it will be back. But sometimes it may take a couple of days of driving. By contacting YourMechanic, you can have a technician come to your home or office with the proper equipment to read the codes and interpret them for you.