MANAAL

dear forum members
my jeep cherokee 2001 alternator not charging the battery, and mechanic told me regulation is through ECM and ECM need to change, i dont have enough money, i am in middleeast, can someone help me to fix my problem,, can i bypass this charging through ECM, and any otherway to charge this battery, i just only want to charge my battery without ECM
thanx in advance

Abovetimberline

You could install an older style regulator but you would be taking a chance od causing more damage to your entire electrical system. I would try and find a used pcm,it is easier to install than a regulator.
depending on your needs you may be able to just charge your battery until you can repair your xj,kinda of a pain but maybe better than the alternative.

5-90

Is he quite sure it's the regulator in the PCM that's gone out on you? Losing the regulator there is quite rare, it's more usually the alternator itself going silly on you.

However, if you're not subject to regular emissions inspection and don't mind having your "Check Engine" lamp on all of the time, you can install an external regulator to bypass the circuit in the PCM. See if you have any marine supply houses or if you have any shops that cater to industrial equipment - either should have what you need (and they can be had over here for US$40-50, which is considerably cheaper than a replacement PCM!)

SeriousOffroad

This guy already has another thread on this subject. Maybe one of the mods can merge the two of them.

MANAAL

thanx timberline for response
and i am waiting from u for used PCM
thanx frankz there i have 2 problems
u see here i am getting response but u told me never
i know all member have different ideas
neway thanx

MANAAL

my ECM Part Number is 56041804AA for jeep cherokee 2001 model,
but i search thousands of sites from US and canada used items and also new
but they are showing the part number some different than this.. sites used parts exactly showing Jeep 2001 cherokee, but having different part number 56041801AA.
because i want to use parts from junk yard and i want to purchase through online,
is there any difference between these parts,, can i still use.. thank u
come on guys reply please

5-90

OBD-II (1996-up) vehicles can be very picky about replacing control parts - particularly if you have to replace the PCM itself!

My thumb rule for a potential replacement is "same year, same model, same drivetrain." So, you'd be looking for a 2001 PCM out of an XJ equipped with a 4.0L inline six, whatever transmission you have (it would either be the automatic - which is the AW4 - or the five-speed manual - NV3550,) and 2WD or 4WD (same as yours.)

The "OEM Number" (56041804AA, in your case) was a much bigger issue with early OBD-I and pre-OBD controls, since there were constant revisions and updates. However, the software revising seems to have become much more stable with OBD-II, and therefore should not be as great a factor.

I'd be especially leery of trying a PCM from another model - as OBD-II progresses, it takes more and more inputs from more and more control modules - and we had (by then) gotten into Body Control Modules, ABS Control Modules, Transmission Control Modules, ... Using a PCM from another model could result in either inputs that the replacement doesn't know how to use, or inputs that the replacement would be expecting (and not getting, because they're not present in the vehicle it's been transplanted into.)

Good luck!

98 JeepJeep

first thing i would have done is removed the alt and have it tested.

MANAAL

thanx 90 and thanx 98
now tell me in clear what i have to do?
can i use the junkyard parts which is available on net.
thank u very much..

i have planning to modify my alternator circuit also without ECM
will it create problem to other electrical circuit? or i will be success?
thank u guys

5-90

If you're going to get a replacement PCM from the salvage yard, note well what I told you above - same year, same vehicle, same powertrain.

Replacing the alternator itself isn't as picky - you just need something that physically fits and has a maximum output rating at least as high as what you're replacing (the 2001 should have a 90A or a 117A unit. Use a 117A to be safe - the regulator circuit will limit the current output as required.)

Installing an external regulator (external to the alternator and external to the PCM) can certainly be done - see my page on the subject here (www.geocities.com/JeepI6Power/presto.html.) This is for using a Prestolite marine regulator (like on a boat installation,) and it works fine. The only problem is that you will get your "Check Engine" Lamp (CEL) lit, and you will not be able to turn it off. This could be a problem if you are subject to regular emissions inspection - like a number of people are over here. However, installing an external regulator simply leaves the regulator circuit in the PCM unused - which is what sets the code in the first place. We haven't figured out a day to "dummy" the regulator circuit to keep the lamp off as of yet.

If you don't mind my asking, where are you located, and are you translating this on your own (you read English) or are you using an online translator (like Babelfish?) Knowing this would allow us to tailor our responses accordingly, and therefore give you something that would be easier for you to understand. I think it a safe guess that English is not your primary language (and it's a pity that I no longer read/write/speak Arabic or Farsi - I'd figure you for one of those. Pashtu and Urdu weren't languages I had much opportunity to learn, but I'd picked up Arabic in Egypt and Farsi in Turkey.)

MANAAL

thanx once again 5-90
actually i am indian and i know the english reading, writing,and spaeking as well,
i am working here in qatar ( middle east ), thats fine that ur atleast responsing well, yeah i want the external regulator, because i cannot purchase new PCM here is very costly for that i am searching from salvage yard, but as u told me it is not easy to install , so i have now planned that i should use extenal regulator for my dynamo. which i can fix it and regulate it.
but one thing i want to know how to bypass this ECM circuit ( unused )?, which alternator i reuiqred?, because i have 2001 model cherokee.
and what will be the wiring diagaram
which can charge the battery?
please give me some more general idea so i can do it that
thank u very much
i am waiting for ur response

5-90

OK - I wanted to know how you were translating, because Babelfish (and other online translators) tend to cause "errors in translation" that can get in the way.

You won't need to do anything to bypass the circuit in the PCM - it will simply go unused. If you look at the page I gave you the link to earlier, you can see how it's done (the specific wiring schematic will vary according to the specific regulator being used, but you can get the idea.) Options include:

- Marine-style external alternator ("dynamo" - haven't heard that word in years...) regulator
- Replacement outright with an alternator having an inbuilt regulator (Delco SI or CS series comes to mind, but you'd have to work on the bracketry and convert the Delco to a "one-wire" or "self-exciting" setup. Probably easy enough - they're common over here.)
- 1970's Dodge/Chrysler external regulator, wired in to control the Nippondenso alternator you currently have (which should work neatly, the same way as the first option, and might be more available to you.)

The first option should include an instruction sheet with the regulator which will tell you specifics of how to hook it up.

The second option will simplify the wiring, but you'd have to figure out how to mount the thing.

The third option is similar to the first, but you'll need to find a service manual locally (check the library?) to see how it's wired up.

MANAAL

thanx ur immediate response
i will search the good auto electrician here and tell him the same
and i will search the alternator and regulator
but here alternator also costly
i think my alternator is working i will check through the mechanic

do u have any idea who are rebuilding the spares like computers, chips, pcm etc,
so i can give them detail and follow up
thank u

5-90

Rebuilt electronics? The only outfit I can think of offhand is A1Cardone - but I'm not sure if they do business overseas (likely, but I can't guarantee it.) Have you checked online?

You might also want to check through ACDelco - I think they carry parts for most major makes (new and reman,) and I'm fairly sure they'll do business overseas.

shawnmf

all i did was charge the battery and when i put it back in it started but did not charge...so while it was running i was touching the wire on th e back of the alternator and i heard it kick in and its been fine all day actually a lil better 13.8-13.9 volts so i would check that if b4 you go and get a new alternator