都總結好了, 就這樣寫給卡公司, 除了coolant overheating will not trigger check en

coolant overheating will not trigger check engine light, 值得商榷。我推理, Coolant overheating will lead to engine overheating,  then will trigger the light. 

強調一下, 有check engine light,一定有診斷嗎。 都沒有給診斷碼, 就是忽悠人。