The check engine light is grounded at the ecu and the cluster normally supplies a positive feed to the bulb. When you cycle the key 3 times the ecu grounds pin 32 of the ecu to light the bulb and flash the codes. All you need to do it get a bulb and hook one wire of the bulb to battery positive. Pull back a little of the coating on the black wire with a pink trace that goes to pin 32 on the ecu. Connect the other side of the bulb to the wire and with the bulb hooked up do the key cycle to get the fault codes. The bulb will act like your check engine light.
Thanks Que89 its been raining over here but as soon as it stops ill check it out n let u know how it goes....by the way, I was with another yj owner today and I was able to find the fuel filter on his easily but there is nothing on mine....he said that is probably inside the gas tank....any input on this?
Fuel filter should be by the frame rail in the rear left hand side just in front of the tire behind a shield. There is a sock in the tank but no filter. If it isnt there then somehow they bypassed it and that really isnt good. It might indicate a few possible problems with fuel pressure. I think you can add renting a pressure guage to check fuel pressure to the things to do list on troubleshooting.
Yeah someone had already told me where it was at, I thought I wasn't finding it but then I looked at my friends jeep n found it right away, went to the same spot on mine and its missing that cover n there is no filter at all....u think I can just put a universal one to make it easier or u think its gonna affect?
A universal will work but you really need to rent a fuel guage from one of the parts stores tool loan program. Without that filter you definitely can get crap inside your fuel system. Do you have the plastic fuel tank or the metal one?
I think its plastic....the previous owner changed it cuz now u put gas on the side of driver side instead of the back.....he told me it was better. So what I just hook up that pressure machine? Well they probably got instructions where I borrow it from right?
I cant see where you are from because you didnt fill out your profile. Please fill it out. I am going to assume you are in the US. You can rent the fuel pressure guage from any big parts store like advanced for a fully refundable deposit.
To check fuel pressure hook up the guage to the valve on the fuel rail. Start the jeep; pressure should read 31 psi, disconnect the vacuum line to the fuel regulator on the front of the fuel rail and it should jump to 39psi. Rehook the vacuum line and it drops back to 31psi. Shut off the Jeep and it should stay above 20 psi for longer then 20 minutes.
You need to get a bulb on the check engine wire like I suggested too. Buy some wire and a light and socket setup when you rent the guage.