CEL and no code

So I got this annoying problem. My 05 LGT has thrown a CEL twice without a code! This happened today and also 2 weeks ago. Both times I went to my local auto parts store and the scanner displayed "no codes found". Has this happened to anyone else? At this pace I think Im gonna buy a scanner in order to clear the fricking code.

Is the light flashing? Could be a misfire that hasn't set a hard code yet

Yea Ive been to a different store each time.

 

Well the CEL stays solid and the cruise blinks... might be a misfire because the engine makes kind of a coughing noise when idling every now and then.

Then you should look at the "Pending" codes and see if they offer something. Not all code readers do read the pending codes.

I had same issue

 

FYI 05 have built in code reader it will display the code

 

Y your left knee there is a small fuse box inside there tucked away in tape there are two white connectors and two green

Plug the two green ( I think) together and the when you turn your key on hit the trip meter during gauge sweep and the codes will be displayed in the display

The connectors can stay together for life if you want

To clear the codes you only need to disconnect battery

 

Or if your sly you can pull the fuse for the ECM so you won't loose your audio presets

Mine did this the other day too. Started it up after I'd been in to the store and got a CEL. Had my scanner handy and nothing came up.. the code cleared itself after about 2 mins and still no code.. Been driving fine since. *shrug*

@ehsnils

I didnt know about pending codes... so what exactly mean? maybe secondary codes?

 

@frank_ster

Yea I read about that one the other day. I took I quick peek under the panel but couldnt locate those cables. During this week I will try to look better for them.

 

So I gotta connect the 2 loose green plugs? Can you guys confirm the color.

 

Nice tip to pull off the fuse of the ECM for reseting it.

Pending codes are codes that the ECU has detected but that can go away again, and they are stored in a different list. In some cases several cycles are needed before a pending code becomes a permanent.

 

But my suggestion is that you should buy a code reader. I bought one at Sears once. But avoid the cheapest versions. If it is as in your case having a code reader in the car means that you can plug it in as soon as the light goes on and then you may catch a sporadic error that goes into hiding when you end up at the shop.

Also don't' freak out after you reset the ECU, the engine will crank for a few seconds before it fires.

Pending codes are codes that the ECU has detected but that can go away again, and they are stored in a different list. In some cases several cycles are needed before a pending code becomes a permanent.

 

But my suggestion is that you should buy a code reader. I bought one at Sears once. But avoid the cheapest versions. If it is as in your case having a code reader in the car means that you can plug it in as soon as the light goes on and then you may catch a sporadic error that goes into hiding when you end up at the shop.

 

but the car has built in code reader. no need to spend the cash

 

Also don't' freak out after you reset the ECU, the engine will crank for a few seconds before it fires.

 

yes ^ also if you simply turn the key to ignition and wait 10 seconds the it will start right up.

 

this 10 second peroid is the system doing some calibrations to the drive by wire throttle body.

@ehsnils

I didnt know about pending codes... so what exactly mean? maybe secondary codes?

 

@frank_ster

Yea I read about that one the other day. I took I quick peek under the panel but couldnt locate those cables. During this week I will try to look better for them.

 

So I gotta connect the 2 loose green plugs? Can you guys confirm the color.

 

Nice tip to pull off the fuse of the ECM for reseting it.

 

 

oops its the white ones i just confirmed.

 

if you plug the green ones together the car will not blow up.

 

the wires are there tucked away keep looking they are there.

 

also the built in code reader also reads chassis and airbag codes

i love it!!!

Wow thank you frank_ster going to give that a try