One problem related to service engine light on has been reported for the 2005 Cadillac CTS. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Cadillac CTS based on all problems reported for the 2005 CTS.
I just purchased this car in February 2019 and it went down in late April or early may of this year. The service engine light would come on for a few days then it would go off for a few days. The engine would rattle when first cranked and then it got to the point where it would constantly keep trying to crank but never would and now it is completely out. I had it towed to mechanic and was told that they had to put 5 quarts of oil in it but I had the oil changed a month before the car died. They say the oil is going somewhere but where? I was also told the timing chain had failed. When this happens it can cause the pistons and everything else to fail with the engine. It will cost me over $2000 to get repaired. This is ridiculous! something needs to be done about this. Cadilliac makes everything so expensive so I would not recommend getting one unless you can absolutely afford it and not be in debt behind it. I was in love with this car but this is horrible. This is my second time trying to get it repaired and now I'm done.