2006 jeep wrangler rubicon check engine light

Anthony1 · Oct 30, 2012

I have a 06 wrangler rubicon unlimited with a 4.0 and 6spd. My problem is I keep getting the check engine light in the afternoon. When I check the code it says the gas cap is loose. So I get a new cap and the code now comes on in the morning.:eeek: I assume its a bad cap wrong it still comes on only in the morning. I have checked all the fittings on the filler and everything is tight.

Any ideas?

Murkman · Oct 30, 2012

Anthony said:
I have a 06 wrangler rubicon unlimited with a 4.0 and 6spd. My problem is I keep getting the check engine light in the afternoon. When I check the code it says the gas cap is loose. So I get a new cap and the code now comes on in the morning.:eeek: I assume its a bad cap wrong it still comes on only in the morning. I have checked all the fittings on the filler and everything is tight. Any ideas?

Check the Charcoal cannister vent. Mine does it all the time just clear the gunk and you should be good to go. Mine see's dust weekly and it needs cleaning every other week or so.

Anthony1 · Oct 30, 2012

Murkman said:
Check the Charcoal cannister vent. Mine does it all the time just clear the gunk and you should be good to go. Mine see's dust weekly and it needs cleaning every other week or so.

OK thanks is it mounted under the hood on the firewall?

KarlVP · Oct 30, 2012

On my 98 TJ it's under the hood on the inner drivers side fender.

Avanteone · Oct 30, 2012

The code isn't saying gas cap loose. That may be what a generic scan tool says, but it's for an EVAP system leak. We also see the NVLD's (leak detection pump) fail VERY VERY commonly on these rigs.

Anthony1 · Oct 30, 2012

Avanteone said:
The code isn't saying gas cap loose. That may be what a generic scan tool says, but it's for an EVAP system leak. We also see the NVLD's (leak detection pump) fail VERY VERY commonly on these rigs.

How do I know if its the pump?

Avanteone · Oct 30, 2012

Anthony said:
How do I know if its the pump?

Pay a shop to diagnose it, or guess. :fawkdancesmiley: It requires more than a generic scan tool to diagnose it. You will need a good scan tool that has the ability to operate and monitor the operation of all the EVAP system components.

Dain Bramage · Oct 30, 2012

Avanteone said:
The code isn't saying gas cap loose. That may be what a generic scan tool says, but it's for an EVAP system leak. We also see the NVLD's (leak detection pump) fail VERY VERY commonly on these rigs.

X2. A gas cap loose code is basically telling you that the EVAP system has a gross leak, which can be caused by an NVLD pump. Before condemning the pump, do a visual inspection of all the EVAP lines from the tank to the engine.

Anthony1 · Oct 30, 2012

How much will you charge to diagnose it John?

Avanteone · Oct 30, 2012

Anthony said:
How much will you charge to diagnose it John?

It really depends on how readily the problem presents itself once we get into it. We're $95/hour, and figure on half hour to one full hour to figure it out for sure.

Anthony1 · Oct 30, 2012

Avanteone said:
It really depends on how readily the problem presents itself once we get into it. We're $95/hour, and figure on half hour to one full hour to figure it out for sure.

OK thanks. I'm going to check a couple more things on it. I might be calling you next week to set up a time.

Anthony1 · Nov 3, 2012

So I cleaned the little canister on the drivers fender and the light was off for a couple days but came back on this morning.

Corey Y · Nov 3, 2012

Disconnect the light :haha:

Avanteone · Nov 3, 2012

Crazy Daze said:
Disconnect the light :haha:

Fail.... for a number of reasons. It will still fail emissions, assuming it's required. And more importantly, you won't know if something goes wrong that IS more serious.

Yeah, the evap system can take several days and/or drive cycles to trigger the code again.