Questionreplaced engine from a 20001 Sonata straight drive, engine doesn't have power; called Hyundai tech in another state who said it might be in "limp mode". Can this be corrected? Please explain necessary procedure to correct.
AnswerIf the transmission is in limp-home mode (3rd gear only), you'll need to locate and repair the issue to allow it to shift. In this case, the check engine lamp should turn on and the transmission won't shift gears.
To solve this issue, you'll need to approach it systematically.
-- Check the engine control module (ECM) and transmission control module (TCM) for diagnostic trouble codes (DTCs). This has the potential to lead you directly to the component causing the issue. If there are DTCs, investigate the components and circuits referenced by the DTCs.
-- If there are no DTCs, determine whether the problem is engine or transmission related. Does the engine rev normally? Does the transmission shift gears at all? If you're unable to figure out whether the issue is with engine or transmission on your own, you'll need to seek out assistance, either professional or otherwise, from someone who is familiar with how different performance issues will feel.
I'm going to ask that you work on the above, and if necessary, follow up. Because of the numerous possibilities, that'll help me keep answers to a manageable length.
