jeepwillyscj2a

I couldn't find anything pertaining to this issue so I thought I would do a quick write up to hopefully help someone else with similar problems. For Reference my Jeep is a 2001 Cherokee 4.0 Automatic.

So I was driving on the Interstate when my check engine light came on and before I could get to an a exit to check it began to flash. When I pulled the code it was a P0202 cylinder 2 injector circuit malfunction, along with some misfire codes cause by the malfunction (http://www.obd-codes.com/p0202, P0201, P0203, P0204, P0205 and P0206 are all similar codes just for different injectors). There was also white smoke pouring out of the exhaust when I got it parked that smelled like fuel. Turned out to be a stuck open injector.

Automatically I assumed it was an injector and bought one (BWD part#63839). While replacing the injector I noticed that the wiring to the connector was exposed and the wires were crossing. So I also replaced the Injector connecter (BWD Part#PT5754). Neither repair fixed the stuck open injector.

(If I did this again, I would switch the injector with one I know works for the possibly failed one. That way you know if the code switches cylinders it is the injector.)

That is when I found this video.
While it is for a 3.3 caravan the same diagnostic principles apply. Unlike the video I had no shorts to ground in the wiring so I my problem was with the driver in ECM. Which means the ECM has to be replaced.

My assumption is that the crossed wires burnt up the driver in the ECM causing it to stay open.

BUYING ECM's

All 2001 Cherokees with an automatic will list part #56041801AD so this is the ECM you need BUT this the important part make sure the Cherokee you are taking it off doesn't have a chipped key. These Ecm's will not reprogram to another jeep because they have been programmed permanently with the Security Pin.



I thought some of you might like this link as well I haven't seen it on here:
PDF's for service manual and parts catalogs that might help in your diagnostics
http://www.xjjeeps.com/

jakegroove

Realize it's a ~10 year old thread - but compiled some info on both of these points as well.
Cross reference as you will: https://thegrovecollaborative.com/p0...it-faulty-ecu/