jpgrifles

Hello all.
I have a 2000 Jeep Cherokee sport with a 4.0 engine Ca emissions, in the fuse box under the hood there are 3 rows of unmarked fuses, in the center row closest to the engine is a 20 amp fuse that keeps blowing.Can anyone tell me what this fuse goes to ?
I recently replaced all three 02 sensors with Bosch sensors from Auto Zone the engine ran great for about 3 days then the check engine light came on and new codes appeared.
P0135, 02 sensor heater bank one sensor one.
P0141 02 sensor heater bank one sensor two.
P0155 bank two sensor one 02 sensor heater malfunction.
P0161 bank two sensor two 02 sensor heater malfunction.
My Hanes manuall test procedure calls for 5.5 to 7 OHMS resistance in the 02 sensor heater circuit, the new Bosch sensors measure 3.4 to 3.6 OHMS. Can anyone tell me if these are defective ? would this cause the 02 sensor heater fuse to blow?
The engine has always ran fine with an occasional # 1 cylinder misfire, cleaning the throttle body and using Sea Foam fuel treatment has always cured the miss.
All help will be appreciated.
Thank you
JPG Rifles

deljer55

I don't know if this will help but check this link. I doubt it reflects the ca emissions cherokee if it is different but hey, I tried. I know it is somewhat frustrating when no one is replying to your post.

http://www.supermotors.net/registry/7625/56030

ET JEEP

Not sure is it is the same fuse, but there is a 20A fuse that powers the ASD relay, fuel injectors and O2 sensors. A short or malfunction in the O2 sensors tends to blow this fuse. You might check the O2 wiring.

ol"blue

Hopefully this will help.>Jeep Cherokee Electrical - 1997 - 2001 XJ Fuse & Relay Identification - Reference guide to the fuses, ratings (Amps), relays and circuit information.
And Welcome to CF

jpgrifles

Thank you all for your help, I'll let you know when i get it working.

aqualordx93

my 2000 XJ has the same issue. Same codes and everything except i havnt replaced any of my 02 sensors yet. Did you figure out what the problem was?

CCKen

Here's the 2000/2001 PDC fuses ID.

The fuse marked "O2S RELAYS" is the O2S heaters fuse.

CCKen

All three Oxygen Sensors? If you have the California Emission exhaust sytem (see pic) you will have four (4) sensors. If you have the Federal Emissions exhaust system you will have two (2) sensors.

Generally, the XJ 4.0 doesn't like Bosch Oxygen Sensors. The XJ came from the factory with NTK Oxygen Sensors and the PCM plays well with these sensors. Universal Bosch O2S' are probably the worst sensors you could install.

The pic shows the O2S part numbers and locations of the California exhaust.

On occasion, it has been found that the O2S wiring has been damaged by rubbing on an engine component, like the intake manifold. You may want to examine all the O2S wiring you can get at.

California Exhaust (2000, 2001 50 states):



00/01 systems:


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