One problem related to check engine light on has been reported for the 2008 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Hyundai Sonata based on all problems reported for the 2008 Sonata.
While driving the check engine light and esc light go on simultaneously. When this occurs, the car goes into reduced power mode ("limp mode") and you are not able to drive above 15 or 20 mph. This is a very dangerous situation, especially when driving on the highway. This is a known issue with Hyundai in which they issued TSB #'s 09-FL-003-2 and 10-FL-010. The TSB's address a faulty throttle position sensor which is to be replaced with a new one with different settings than the original. One the part is changed, an update to the electronic control module is required. There are numerous accounts of this incident happening. How can a flaw of this magnitude not warrant a recall?.