I am getting two codes on my 2003 Jeep Liberty.

MIEC

MEMBER
2003 JEEP LIBERTY

I am getting two codes on my 2003 Jeep Liberty: Large and small evaporative emissions leaks. I have repaired all leaks verified the system is closed. Is it possible that a faulty leak detection pump would give the two codes large and small evaporative emissions leaks? I don't know what else to check.

6 Replies

HOMER1967

MECHANIC
875 POSTS

It is possible that you have a bad ldp or pcm.I would have it diagnosed at a shop with a smoke machine.

Was this

answer

helpful?

Yes

Tuesday, December 18th, 2012 AT 12:54 AM

JACOBANDNICKOLAS

MECHANIC
108,133 POSTS

Before you do that, fog the system to see if there are any leaks. They will show up if there is a leak.

SPONSORED LINKS

Was this

answer

helpful?

Yes

Tuesday, December 18th, 2012 AT 12:54 AM

MIEC

MEMBER
26 POSTS

I have pressure tested the entire system and I feel pretty confident that there are no leaks. I am curious as to how the PCM could be bad and only throwing codes related to large and small evap leaks?

Was this

answer

helpful?

Yes

Tuesday, December 18th, 2012 AT 1:45 AM

JACOBANDNICKOLAS

MECHANIC
108,133 POSTS

That is a good question. I would try the smoke test to make sure there are no leaks. I don't think it has anything to do with the PCM.

Was this

answer

helpful?

Yes

Tuesday, December 18th, 2012 AT 1:49 AM

MIEC

MEMBER
26 POSTS

OK I have taken various sections apart and pressure tested for leakes. I have repaired the leaks and I can pressurize a clear path from the purge solenoid to the tank. There are no leaks. Is there a test I can do to verify if the leak detection pump is operating correctly?

Thanks