Actually, now check DTCs in vehicles is easier than before, for there are so many obd2 code scanners can be used to read DTCs and even erase them. And here I am sharing you with one method without using obd2 tools.

For example, how to check for DTCs in Jeep grand cherokees 1993 to 1998? First you need is your key. And then place the ignition key into the ignition slot, and turn to ON (NOT RUN) 3-5 times, count how many times the Check Engine light flashes. The code 55 indicates the end of sequence (this will appear if no codes are present or if the Check Engine light is not on). Finally, go to check for codes that apply to your vehicles.

Generally speaking, now obd2 code scanners technology is so advanced. Therefore, you could use tools like IScancar to check your vehicles without pay too much energy on counting.