So i got a check engine light 2 days ago so i hooked up a scanner and got these codes- P0132,P0135,P0138,P0118. The jeep runs like ****. Is it possible all these went bad at one? Or is one bad sensor affecting the others?

 

Ive got a list of codes somewhere, Ill find it and post if someone hasnt gotten here sooner.

USUALLY if you clear up the lowest code it will clear the others. Ill go find mine.....

 

OK, P0118 is your coolant temp sensor. Visually inspect the wires and make sure nothing is screwy. I think you can disconnect the sensor and use a DVOM to check the volts. I think you should have 5. If there is more than 6, you have a short somewhere.

If not, Id replace the sensor. It SHOULD clear the other codes.

 

ok thank ill give that a look now.

 

Also, just in case, 0132 is O2 sensor short, voltage too high

0135 is O2 sensor heater element failure

0138 is O2 sensor short, voltage too high

the 0118 is probably your problem if this all started all of the sudden. If its been running crummy off and on, and/or you have never changed your O2 sensors, mine as well change them as well if you can afford it. But the 0118 is is your coolant sensor voltage is too high, so its either a short or the sensor is going bad. Start there, see if replacing it clears the codes and go from there.

 

Check the 02 Sensor fuse in the fuse box in your pass. side engine bay.

 

Would that set off the 0118 coolant temp sensor? In my experience, MOST of the time multiple codes will be cleared after fixing the lowest numbered code.

 

just checked the voltage for the coolant temp sensor and got 5.11v. so ima go from there and replace the sensor and see if that fixes my issues.

 

That doesnt sound crazy high, but I dont know for sure. Replacing the sensor definitely wont hurt anything and should be part of long term, routine maintenance. If its never been changed, its basically 14 years old with however many miles on it.

 

so i replaced the coolant temp sensor and the thing runs alot better. ill still scan it later to see if the o2 sensors are bad. if they are ill just have to replace them. thanks alot for your help

 

No prob, man, glad it worked out for you.

If its running like crap from bad O2 sensors, youll be able to tell.

Best of luck!

 

Did you reset the PCM after you changed the sensor? If not, unplug the negative battery terminal and go pump the brake pedal a couple times. that will draw all power out of the system and reset the PCM. Reconnect your terminal and let the computer go through its learning process again.

 

does anyone have a fuse box diagram for the one under the hood? just noticed one of my fuses was blown there but it doesnt say what its for.

 

I have a 99. Fuse 24 in the power distribution center is for the "heater circuit" on the oxygen sensor. It is a 15 amp mini fuse. I'm guessing that is the one that is blown?

It is not that uncommon to see this fuse blow. If it does, you'll have driveability issues and codes.

Replace it. If it blows again, you'll need to replace your oxygen sensors as that is likely what is causing it. May as well replace both of them while you're at it. Use NTK for the best match with the 4.0 engine. Rockauto, Amazon good sources.

 

so i changed out that fuse and BAM the xj is running perfect. saved me some money for now but ill be eventually changing out the o2 sensors.