P0456 Code, Erased but not gone... - JeepForum.com
 
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post #1 of 5 Old 08-02-2009, 07:03 PM Thread Starter
01Limited45324
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2001 WJ 
 
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P0456 Code, Erased but not gone...

My 2001 Grand Cherokee's check engine light came on so I ran a diagnostic and the car returned a P0456 code (small Evap leak).

I checked my gas cap (loose again, might need replaced?) and fixed the probable problem.

I then hooked it up to a handheld Diagnostic and erased the code. However, the light is still illuminated.

My question: If it's not the gas cap, what else could it really be? Does it take a few cycles to get the light to turn off, or does it come off as soon as the problem is fixed?

Yes, I checked wjjeeps.com and did a forum search, but nothing really answered this question specifically.


-Tom

2001 Grand Cherokee Limited
2002 BMW 530i
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post #2 of 5 Old 08-03-2009, 08:31 AM
Double E
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it will take a few cycles to clear as long as

- the code is not triggered again
- another code was also not present at the same time and is still an issue

2000 Laredo 4.7L Selec-Trac. 177K miles, Leather, 245 tires, tow package, crappy CD changer, full size spare, roof cross-rails & sunroof.
Changes & fixes: Rear Addco sway bar & greasble bushings, upgraded headlights, upgraded tail lights, new hood struts (replaced 2X), new rear hatchglass struts, new radiator (replaced 3X), new oil pressure sending unit (replaced 4X), 2 new speed sensors, 2 new door lock actuators, new ignition key cylinder, chrome front tow hooks, Mobil 1 Synthetic 5/30, Purolator Pure One oil filter, EBC slotted & dimpled rotors, EBC Greenstuff pads, new front shocks (replaced 3X), new rear shocks (replaced 2X), new IRO steering stabilizer, new timing chain cover, new water pump, thermostat, new thermostat housing, new high pressure power steering hose, Michelin-X radials, new sunroof assembly, new single-piece lug nuts, new exhaust manifold studs & gasket on driver's side, new Durango alternator. Jeepforum.com sticker, Visit cobaltboatsforum.com when you can!
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post #3 of 5 Old 08-03-2009, 11:16 AM
greasefingers
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a) the charcoal canister could be cracked
b) the vacuum line(s) are broken, dry-rotted or have slipped off
c) the gas cap rubber O-ring is shot causing a leak.

Cheers Steve

94 Black Laredo 4-Liter with QuadraTrac (42RE trans & NP249 TC) 200,000 + miles purchased new

88 Cherokee 2-door with 5speed manual 139K miles(deceased) purchased new
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post #4 of 5 Old 08-03-2009, 12:11 PM Thread Starter
01Limited45324
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Here's another twist: If I do the diagnostic cycle (on-off-on-off-on) it still brings up the P0456 code and then it says done after half a second... Normal?

-Tom

2001 Grand Cherokee Limited
2002 BMW 530i
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post #5 of 5 Old 08-03-2009, 12:48 PM
Double E
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Yes......,

2000 Laredo 4.7L Selec-Trac. 177K miles, Leather, 245 tires, tow package, crappy CD changer, full size spare, roof cross-rails & sunroof.
Changes & fixes: Rear Addco sway bar & greasble bushings, upgraded headlights, upgraded tail lights, new hood struts (replaced 2X), new rear hatchglass struts, new radiator (replaced 3X), new oil pressure sending unit (replaced 4X), 2 new speed sensors, 2 new door lock actuators, new ignition key cylinder, chrome front tow hooks, Mobil 1 Synthetic 5/30, Purolator Pure One oil filter, EBC slotted & dimpled rotors, EBC Greenstuff pads, new front shocks (replaced 3X), new rear shocks (replaced 2X), new IRO steering stabilizer, new timing chain cover, new water pump, thermostat, new thermostat housing, new high pressure power steering hose, Michelin-X radials, new sunroof assembly, new single-piece lug nuts, new exhaust manifold studs & gasket on driver's side, new Durango alternator. Jeepforum.com sticker, Visit cobaltboatsforum.com when you can!
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