Ok guys what are some thins I can check when the engine malfunction light comes on ? I checked the gas cap seems fine , it's a 2013 unlimited I don't have a code reader Igbo is not flashing it's said and the jeep seems to be running fine but light stays on after multiple starts and stops.
Thanks
Dave

 

I'd suggest buy a code reader....even a cheap $20-$30 model will suffice and you'll have it for years to come. Outside of that, run to Autozone or O'Reilly or the likes, and have them pull the code. There is absolutely no way to just guess. Once you have the code post it up and everyone can set you in the right direction on where to look.

 

Stop by a big-box auto parts store (Advance, AutoZone, O'Reilly). They will read DTCs for free.

 

For your engine light, there is also a key switching sequence you can use to have them read out on the dash. Sorry, I don't have that sequence on me at this time but if you Google you can find a discussion on this forum that has it, or maybe someone will be nice enough to post it up.

I would suggest to skip the $20-$30 code readers since you can get those same coses with the key dash read out sequence. Then for codes outside of the ECM/CEL module codes I would recommend jumping to a code reader such as BlueDriver which can read ABS, airbag, everything else you can get by going to a Dealership that they will charge you $80+ for a single scan readout.

I've done the $20 and Superchips readers. They're a waste in my opinion. I've also done the Autoparts store route as well. That's hit and miss. Most cases it's the same results as the dash key sequence, but some may use a code reader that will read ABS. Do either the free dash readout, or jump up to a BlueDriver type scanner if you need more.

 

Turn the key from off to run 3 times, on the 3rd time you leave it in 'run' and watch your odometer.

This will only give you Powertrain codes (P prefix codes) and will not reveal C, B, or U prefix codes.

 

Ok did the key on off thing and the code p0456 came up does that mean Evap system and gas cap not sealing ?

 

Unless you been doing something crazy just recently which would lead you to believe you damaged your evap down below, I'd clear the code, chalk this up to gas cap this one time, and see if it comes back. If it comes back, warrants a further look, but could just be a fluke. Maybe you didn't have the gas cap on well, and after a couple starts throws the code.

A lot of codes like that I chalk up to flukes unless I clear and they pop back up. It does happen from time to time.

 

Smear a little silicone lube up on the gasket at the tank and she'll be ok if it's the gas cap. I had that same code this week and it's gone now.

 

Thanks Karl,
Back at my computer now to pull up my notes.

Read Diagnostic Codes
1. Ign Off-On
2. Ing Off-On
3. Ing Off-On

Codes and check instrument cluster lights
1. Hold Trip reset button
2. Ign Off-On

 

I just went through this gas cap light nonesense on a v-6 Dodge Charger. There is a very small EVAP vacuum pump under the hood, little black thing with the sensor for the EVAP system. The thing is about $20 bucks, that was my problem. Find this thing and check its function.