Welcome guzzle' diagnostic trouble code list web page, Obd-ii diagnostic trouble codes (dtc) has four basic code categories: p - powertrain c - chassis b - body u - future diagnotic systems a breakdown of these categories. Obd-ii (check engine light) trouble codes, Please use our new & improved search engine to find information on your trouble codes. search now! this list contains standard diagnostic trouble codes (dtc's) that. Jeep grand cherokee wj - diagnostic trouble codes, A diagnostic trouble code (dtc) indicates that the powertrain control module (pcm) has recognized an abnormal condition in the system. dtc's are the results of a.