My Cherokee 2000 Engine light is on

[stalaat]

Can someone help me with this , i have cherokee 2000 sport 4.0 , my engine light came on i turned off by the battery it came on again after 2 days , so i toke it seriasly i changed the spark plugs, air filter, changed oli and oil filter , i removed the carbon on that part ( the panel) engine light went off , but now its on again , but i noticed something that when i park the car for a day or far from the sun and heat for sometime when i start the car then the light came on agian , is that have any thing with the engine Tempture? when its cool down it brings the light on
Please help
dealer is too expensive

[b1gfella]

it sounds like it may be the O2 (oxygen) sensor. They are generally mounted in the exaust system so they tend to live in a bad environment. I've replaced them on most every car I've owned at one time or another as they go bad over time just like a spark plug. In most cars they actually look like an odd spark plug mounted in the exaust manifold with a sinle wire coming from it.

[stalaat]

do you think that
it dosent have anything with the fuel or fuel pump,filter?

and what dose this O2 sensor do ?

[b1gfella]

if the fuel pump is an issue you would know it as the jeep would not get any fuel. This would cause the jeep to stop running. I don't believe the fuel pump or the fuel filter are tied into the computer system to trigger a "check engine" light. The O2 sensor is and lets the computer know how to set fuel/oxygen mixture. They can go bad with little or no diffenerence in engine performance until you hit extreme conditions of altitude or temperature. They are easy to replace if you can get at it and they are usually about 50 dollars or less at the parts store and can be changed like a spark plug.

If your still confused or worried find a garage (not necessarily the dealer), that has a code reader and see if they can pull the code and tell you what it is.

[Ghetto2315]

Take your XJ to your local AutoZone to have them scan for codes for free.

Also, take a look at this and see if this may be your problem:



2000-2001 JEEP CHEROKEE
ROUGH IDLE / MULTIPLE CYLINDER MISFIRE

------------------------------------------------------------------------------------------
1801301 - ROUGH IDLE AT COLD TEMPERATURES
Date: 06/11/01
Model Year(s): 2000

Description: Some vehicle engines may exhibit a rough idle and / or Malfunction Indicator Lamp (MIL) light on condition upon initial start-up after a cold soak when temperatures are below 50 degrees F (10 degrees c). This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (Cal level 00Cal15C).




1801001 - ROUGH IDLE AT COLD TEMPERATURES
Date: 04/20/01
Model year(s): 2001

Description: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 4.0L (ERH) ENGINE BUILT PRIOR TO APRIL 30, 2001 AND CALIBRATION LEVEL PRIOR TO (LESS OR LOWER THAN) THOSE LISTED IN THE OVERVIEW ABOVE. This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (WJ/TJ ? calibration level 01Cal14C, XJ ? calibration level 15B.)

Details: Some vehicle engines may exhibit a rough idle and/or MIL light ?on? condition upon initial start-up after a cold soak when temperatures are below 50°F (10°C).




0900303 - 4.0L MULTIPLE CYLINDER MISFIRE
Date: 08/01/03
Model Year(s): 1999-2004

Description: NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 4.0L ENGINE. This bulletin involves inspection of all engine exhaust valves and a decarbonizing procedure if necessary.

Details: The customer may experience an incident of engine misfire during certain vehicle operating conditions. The misfire may occur when the vehicle is operated between 50 - 70 MPH and under light loading conditions, e.g. slight uphill road grades. This condition may occur at all ambient conditions, but is more noticeable when ambient conditions are less than 0 C (32 F).

If the vehicle is equipped with On-Board Diagnostic (OBD), a MIL illumination may also have occurred due to Diagnostic Trouble Code (DTC) P0300 - Multiple Cylinder Misfire. Various single cylinder misfire DTC?s may also be present. If the frequency of misfire is high the Powertrain Control Module (PCM) may place the engine in ?Limp-In? mode.

The misfire condition may be caused by one or more engine exhaust valves that are slow to close. Late closure of an exhaust valve may be the result of no valve rotation and associated build up of carbon on the exhaust valve stem.

This condition may occur when the engine is not allowed to run at engine RPM?s that are greater than 3,200 RPM. At 3,200 RPM or higher the engine exhaust valves will rotate if not impeded by high carbon deposits. Low engine RPM?s and high carbon deposits are associated with short trip driving where the vehicle engine is not allowed to fully warm to normal engine operating temperatures. Cold ambient temperatures will increase engine warm-up time and add to the opportunity of carbon deposit build-up on the stem of the engine exhaust valve.




1803103 - 4.0L ROUGH ENGINE IDLE AFTER RESTART FOLLOWING A HOT SOAK
Date: 09/05/03 (supercedes 1802702 dated 09/06/02)
Model Year(s): 1999-2004

Description: NOTE: This bulletin applies to vehicles equipped with a 4.0L engine. This bulletin involves the installation of a fuel injector insulator sleeve.

Details: Customers may describe a 20 to 30 second rough idle following the restart of a heat soaked engine. This condition may be most noticeable when the engine is restarted following a prior 10 to 20 minute heat soak in hot ambient conditions of approximately 32 C (90ºF) or higher. This condition may be consistent with short city stop-and-go driving trips and can be aggravated by the use of fuel with a high ethanol content. Depending upon various conditions a MIL may occur due to DTC P0303 - Cylinder #3 Misfire.

This condition may be caused by heat from the exhaust manifold that following engine shut down migrates to the area around injector #3 and causes fuel vapor to form within the injector. This in turn may cause a momentary misfire of cylinder #3 until the fuel vapor is cleared of injector #3. The insulator sleeve lowers the injector #3 temperature to a point below which the fuel will not normally vaporize.

If vehicle exhibits a rough idle, and if a misfire of cylinder #3 is observed following a 10 to 20 minute hot soak, perform the Repair Procedure.

Parts required:
56028371AA Ignition Wire Shield

Repair procedure:
1. Cut insulator sleeve, p/n 56028371AA, to make two (2) insulator sleeves about 25-30 mm (1 in.) in length. See diagram.
2. Install one sleeve around injector #3, with the slit on the upward facing side of the injector. Install the other sleeve with the slit on the downward facing side of the injector.
3. Confirm sleeve is flush to intake manifold surface around injector.
4. Check injector #3 wire and ensure that the injector is rotated to a 2 o'clock position (from driver?s side of vehicle).

[stalaat]

waw , if im facing ROUGH IDLE AT COLD TEMPERATURES they will only do reprogramming ?
because as i said when the car is cold or parked a whole day after i start it the light comes on in about 1 min. or maybe less in secounds.
so ist ROUGH IDLE AT COLD TEMPERATURES

[stalaat]

what is manifold ?do

[saljo]

Maybe a evap leak?

[gtmud]

WOW! Slow down, first your 00' XJ has (4) four O2 sensors, they tell the computer how the engine is burning the fuel, rich or lean. If they do go bad, you will need to go and Purchase the Haynes manuel, look under emmisions. There is a part in there that tells you how to pull the codes your self. If you are still having problems try auto zone, if that doesn't work then go to the dealer, but I think you'll get the code by pulling it yourself(code)
Also, your engine light will be set off by an electronic componant. To reset the computer, disconnect the NEGATIVE cable for about 5 minutes. reconnect and see if light comes on. Try this first. My 00' Xj had the light come on, I reset the computer, and it stayed off. At 90K still running well with K&N FIPK, and Magna Flow Exhaust. Like I said, reset your computer first, then if it comes back on, pull your codes by following the Haynes Manual you can buy at any autoparts store. Good luck.

[stalaat]

I went to my garage i deal with and he checked the car he discovered with the (ODBII) three codes with three sensors that i have problem with :
1- P0113 IAT sensor voltage high (Intake air temp. high)
2- P0118 ECT sensor voltage too high (Eng. coolant Temp. high)
3- P0161 OS2 Heater Failure
i want to know what each one of them do , or how it can infect the car?
and ist serious issue or it can wait for some time to change it?
Please I need help

[gtmud]

Ok, now we have something to go with. First, "1" - This sensor I believe is at the front leading edge of the intake manifold. "2"- Is in the thermostat housing, and "3" I think is the heater for the #2 Oxygen sensor. I would replace the O2 sensor first, then the I.A.T. sensor. reset your codes, and see what happens. Do you have idiot lights, or guages on your XJ? Your haynes manual will help you with identifying your sensors. I think the #2 O2 sensor is the sensor just below the first "can" off the exhaust manifold closest to the firewall.

[stalaat]

My Cherokee have a little small shaking when i park or stop in a red light anyway when the car is not moving , dose those sensors problem have any thing to do with this problem and i notice that the RPM shakes too a little bit
any ideas???

[gtmud]

Get these sensors replaced! Then reset the computer and see where you are at. Yes, if there is a misread in temp, or burn mixture(o2) Jeep will run a little ruff. First have to change those sensors. There is something wrong, if there is a code on them.

[stalaat]

i have replaced the :
IAT sensor voltage high (Intake air temp. high)
ECT sensor voltage too high (Eng. coolant Temp. high) and we found out that i have 5 O2 sensors in the car 3 under the engine and 2 in the back of the car i changed the last 2 and cleaned the 3 sensors under the engine , now the light went off and i will wait and see if it will stay off or come back again hope not

[gtmud]

Sounds good. I suppose I should look at mine 91K+ never had a problem, but I will look around and figure out which O2 sensor is whish, as far as the number ID goes.