Check engine light
12-11-2013, 07:16 AM
#1
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Check engine light
My 2000 XJ is throwing codes, 2 O2 sensor, a fan relay, and an emissions purge valve code. I've replaced all 4 O2 sensors and the purge valve. The strange part is it only throws the codes when I turn the heater control **** on the dash, I can let the jeep run and drive it with the HAVC system off and get no codes. The jeep runs fine with the cel on. Any help or ideas would be great.
12-11-2013, 07:27 AM
#2
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Year: 1996
Model: Cherokee
Engine: 4.0
My 2000 XJ is throwing codes, 2 O2 sensor, a fan relay, and an emissions purge valve code. I've replaced all 4 O2 sensors and the purge valve. The strange part is it only throws the codes when I turn the heater control **** on the dash, I can let the jeep run and drive it with the HAVC system off and get no codes. The jeep runs fine with the cel on. Any help or ideas would be great.
12-11-2013, 07:33 AM
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Year: 1996
Model: Cherokee
Engine: 4.0
if you have bad o2 sensors, your fuel mileage should suffer noticeably. as far as the fan relay goes, you can test it by turning your AC on. does the aux electric fan turn on if the AC is on?
12-13-2013, 05:05 PM
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One of the first thing I did was check all of the fuses, all good. So today while chasing the gremlin, I read in the owners manual that fuse #10 in cab affected all the systems that are throwing codes. I knew that I had checked all the fuses and none were blown, but I rechecked anyway. What I found was fuse #10 was missing, I put a fuse in and the codes are gone! Thanks for the input. Hopefully Im fixed.
12-14-2013, 08:39 PM
#7
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Year: 2001
Model: Cherokee
Engine: 4.0 L, Inline Six
My 2000 XJ is throwing codes, 2 O2 sensor, a fan relay, and an emissions purge valve code. I've replaced all 4 O2 sensors and the purge valve. The strange part is it only throws the codes when I turn the heater control **** on the dash, I can let the jeep run and drive it with the HAVC system off and get no codes. The jeep runs fine with the cel on. Any help or ideas would be great.
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12-14-2013, 09:35 PM
#8
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Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
It sounds like you've got a massive short and/or bad ground in the system. You need to go over all the wiring and connectors, refreshing where appropriate and checking for rodent damage, melting, or chafing.
This link, while written for 1987-1990 XJs, has pertinent information on how to clean the grounds, refresh connectors, and perform an inspection:
https://www.cherokeeforum.com/f51/cr...x-tips-153657/
This link has engine bay grounds for 1997+ XJs:
http://www.naxja.org/forum/showpost.php?p=245993828
After you clear the codes and drive around with no problems, exactly which ones come back when you run the HVAC?
CEL is only on because there's a problem... take care of your **** and you don't have problems. If you're too lazy to fix your Jeep that's your business but don't go around telling people it's normal to have a broken vehicle.
This link, while written for 1987-1990 XJs, has pertinent information on how to clean the grounds, refresh connectors, and perform an inspection:
https://www.cherokeeforum.com/f51/cr...x-tips-153657/
This link has engine bay grounds for 1997+ XJs:
http://www.naxja.org/forum/showpost.php?p=245993828
After you clear the codes and drive around with no problems, exactly which ones come back when you run the HVAC?
CEL is only on because there's a problem... take care of your **** and you don't have problems. If you're too lazy to fix your Jeep that's your business but don't go around telling people it's normal to have a broken vehicle.
12-15-2013, 05:08 AM
#9
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Year: 1996
Model: Cherokee
Engine: 4.0
It sounds like you've got a massive short and/or bad ground in the system. You need to go over all the wiring and connectors, refreshing where appropriate and checking for rodent damage, melting, or chafing.
This link, while written for 1987-1990 XJs, has pertinent information on how to clean the grounds, refresh connectors, and perform an inspection:
https://www.cherokeeforum.com/f51/cr...x-tips-153657/
This link has engine bay grounds for 1997+ XJs:
http://www.naxja.org/forum/showpost.php?p=245993828
After you clear the codes and drive around with no problems, exactly which ones come back when you run the HVAC?
CEL is only on because there's a problem... take care of your **** and you don't have problems. If you're too lazy to fix your Jeep that's your business but don't go around telling people it's normal to have a broken vehicle.
This link, while written for 1987-1990 XJs, has pertinent information on how to clean the grounds, refresh connectors, and perform an inspection:
https://www.cherokeeforum.com/f51/cr...x-tips-153657/
This link has engine bay grounds for 1997+ XJs:
http://www.naxja.org/forum/showpost.php?p=245993828
After you clear the codes and drive around with no problems, exactly which ones come back when you run the HVAC?
CEL is only on because there's a problem... take care of your **** and you don't have problems. If you're too lazy to fix your Jeep that's your business but don't go around telling people it's normal to have a broken vehicle.
12-15-2013, 11:38 AM
#12
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Year: 1999
Model: Cherokee
Engine: 4.0
One of the first thing I did was check all of the fuses, all good. So today while chasing the gremlin, I read in the owners manual that fuse #10 in cab affected all the systems that are throwing codes. I knew that I had checked all the fuses and none were blown, but I rechecked anyway. What I found was fuse #10 was missing, I put a fuse in and the codes are gone! Thanks for the input. Hopefully Im fixed.
I know rats and chipmunks make nests and eat wires in the XJ but I didn't know they had the ability to remove fuses.
This is Twilight Zone ****.
Someone school me on this please.
12-15-2013, 12:04 PM
#13
Herp Derp Jerp
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Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
I've read several posts over a period of time where the OP found #10 fuse missing from the JB. For the life of me, I can't figure out why/how fuse #10 is just suddenly missing. Jeeps with this fuse came from the factory with it installed, and yes, it does power lots of circuts. How is it that suddenly a CEL pops up or circuits just suddenly quit working only to find out #10 is missing.
I know rats and chipmunks make nests and eat wires in the XJ but I didn't know they had the ability to remove fuses.
This is Twilight Zone ****.
Someone school me on this please.
I know rats and chipmunks make nests and eat wires in the XJ but I didn't know they had the ability to remove fuses.
This is Twilight Zone ****.
Someone school me on this please.
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