Check engine light just came on

[Reidminer]

Hello everyone, so I’ve got a 01 wrangler with the 4.0, manual 5 speed, 110k miles. Since I bought it in October, not a single light has popped up on the dash. Until today. While driving home from work(about a 6 mile trip) and I noticed when I urned onto my street that my check engine had come on sometime during this drive(it wasn’t on when I drove to work in the morning). Before I go the route of having my mechanic buddy check it out, are there any ideas you guys might have as to why this came on? I feel nothing wrong, nor hear anything wrong. I did have the clutch replaced(professionally, by a well trusted mechanic) about 2 months ago. Is there anything that I could do to narrow down the potential issue myself? I’ve got decent, basic auto knowledge and able to learn quick lol.

 

[bromel]

There are so many possible things it could be, so you need to get the codes read. You can bring it to an Autozone or other parts chain and they should read it for free. Better yet, buy a code reader online.

Could be as simple as an evap leak because you didn't tighten the gas cap, or it could be something more serious. The forum can only help if you get the specific codes.

 

[JEEPCJTJ]

Get in the Jeep and turn the key on, then off, then on and off again, then on one more time. At that point the odometer will tell you what codes are in there. They all start with a P.

 

[D M]

X2 to the key trick. On(but not cranking) and off 3 times and your odometer should read a set of numbers such as P0145 etc...

 

[Reidminer]

Get in the Jeep and turn the key on, then off, then on and off again, then on one more time. At that point the odometer will tell you what codes are in there. They all start with a P.

Damn for real? Yeah I’ll give that a shot tonight. I never knew that was a thing, thanks!

 

[Reidminer]

There are so many possible things it could be, so you need to get the codes read. You can bring it to an Autozone or other parts chain and they should read it for free. Better yet, buy a code reader online.

Could be as simple as an evap leak because you didn't tighten the gas cap, or it could be something more serious. The forum can only help if you get the specific codes.

Alright cool, my dad has a code reader for sure. I’d be able to do that tomorrow afternoon. If I’m not noticing any issues driving it, I’m good to drive it until then right?

 

[Preacher 1979]

Just do the key thing and Google the code. Will tell you what to look for.

 

[AndyG]

We should all be suspect for owning a vehicle that displays it's on codes.

 

[Oldguy]

Most of the time a non blinking check engine light is emissions. Blinking means, oh shit

 

[03coloradowrangler]

We should all be suspect for owning a vehicle that displays it's on codes.

truck has intermittent rear o2 code (exhaust leak post cat but pre o2 sensor) & sometimes the abs light comes on (chaffed sensor wire from tire rub). otherwise runs like a raped ape with 275k miles. Jeep on the other hand, as soon as that light pops on, out comes the code reader and promptly repaired.

 

[AndyG]

Never rule out loose pre cat bolts . Trust me.

 

[2001slvrstntj]

Did you get the code, the key trick tells you the code...no reader required?

 

[Reidminer]

Did you get the code, the key trick tells you the code...no reader required?

Once I got to work( I work at a dealership, just not a mechanic myself(yet!) I did the key trick as that’s what a mechanic said to try first as well. It showed P0340, cam position shaft sensor. So he said before I go about replacing it($75 for an oem sensor) to reset it and see if it pops up again. I did that, and sure enough right before I got home the light came back on...did the key trick and still just showed P0340. So is my best option to go the OEM route? I’ve heard that aftermarket sensors are sorta hit or miss

 

[Nick B]

So is my best option to go the OEM route? I’ve heard that aftermarket sensors are sorta hit or miss

Usually go with the OEM ones. Aftermarket ones can work but sometimes you'll get a broken one right out of the box. A cam position sensor is a somewhat common issue for Jeeps so I'd just go the safe route and get an OEM one.

 

[2001slvrstntj]

Yep, I think OEM is the best route. Not that tough to replace and I think that can stand you at some point. I did mine a while ago and don't recall it being tough to do.

 

[Reidminer]

Yep, I think OEM is the best route. Not that tough to replace and I think that can stand you at some point. I did mine a while ago and don't recall it being tough to do.

Yeah that’s what the mechanic was saying too. I’ll all for OEM products in most situations so I’ll definitely do that. Thanks!

 

[AndyG]

OEM or Jeep no move sometimes.

 

[jayeljeep]

Hello gents, new owner of a 04 TJ. Bone stock, 1 owner, no rust, 97k miles. Had it for 3 was now and check engine light came on. Steady light, not blinking. The “Key Trick” above isn’t showing anything. Am I doing something wrong?

 

[RocknLJ]

Hopefully this link works

 

[RocknLJ]

Let us know what codes it shows and we’ll try to help.

If you plan on owning a TJ for a while, I’d recommend downloading the FSM’s from this forum and invest in a bi-directional code reader.

Good luck!