What does code PO351 mean
this means there are ignition coil issues. I don't have my book close by to give you detailed information on what else to check but it is an ignition issue that is causing the PCM to read a failed ignition coil, so it could be as simple as a bad ground on the coil a corroded connector going TO the coil and I have even seen a bad coil to cap wire trigger this one so if you have NEVER done a tune up, and have original spark plugs and wires you may be getting this code in error as well. Start by checking the plugs going to the coil and make sure the electrical connections are clean and solid, make sure the lead from the coil to the cap isn't arcing out anywhere, and the cap and rotor are good and not arcing out across dirt or soot on the inside of the cap, as this will show up as a bad coil as well. If this doesn't work before spending money on a new coil, pull some of your spark plugs (one at a time and put it back before pulling another) and check their condition. if they are bad, replace them with properly gapped plugs of the correct type. WORD OF WARNING Jeep engines do not care for copper or platinum plugs! Good old fashioned Autolite are your best bet in stock jeep engines. I have decades of experience with these engines, and the high end plugs Just do NOT work very long, so don't waste you time or money n them. when you are checking the plugs check the cables with a simple DVM (digital volt meter) set to the Ohms scale and check end to end for a reading. if you don't get one the cable is bad. you can get these meters for as cheap as ummm free with a coupon from Harbor Freight or without for about seven bucks. If this doesn't fix it NOW check the coil itself, using the same cheap meter, check across the input for continuity again using the Ohm scale if you don't get a reading the coil is bad. You CAN go straight to the coil and skip the rest of these checks, however, ignition coils are simply a special type of transformer, and transformers that are going to burn out on their own, do it early in their lives. those that last over 15 years generally have something that caused them to burn out, and in the case of ignition coils it is usually stress induced by lack of maintenance of the overall ignition system (this is where being an Electronics Engineer comes in handy). I'm 55 and been spinning a wrench since I was a kid when my father, who was a product of the Great Depression taught me REAL auto mechanics, as well as a host of other skills (I even know how to do lead body work. no bondo filler for me!) because he recognized the importance of self sufficiency.
