P0443 on Jeep Grand Cherokee...

[mvbighead]

Just looking for some feedback on this ongoing problem I've been dealing with. Got this code some time back, and now it is being thrown again:

p0443 - EVAP Emission System Purge Control Valve Circuit.

Vehicle is a 2000 Jeep Grand Cherokee with the 4.7l V8.

I had replaced the Purge Control Solenoid myself after some research and given the ease of the task, and it seemed like the problem subsided for a while, but then the dreaded code was thrown again with no symptoms in driving. Actually, replacing the solenoid did seem to fix an issue where there was a lot of pressure in the gas tank when opening the gas cap to fuel up.

I did also have a mechanic check it out, and all appeared fine electrically to him, to which he suggested that if problems persist, it might be the PCM/ECM. That was about 4 or more months ago.

And now, I have the code again, and what seems like a symptom that is directly tied to it: Recently had some very slow traffic (4-way stop signs on a major intersection due to power outage) and while idle and rolling forward, the car stalled almost to the point of dying. Then, at a similar intersection, it did the same thing again, only this time it actually died. Fired right back up the ignition and drove home without issue while maintaining any condition above idle. It only seems to stall when running idle for an extended period.

So the question then becomes, does the ECM seem like the logical next step? I am considering replacing it anyway in hopes of getting this thing nipped. Presently considering buying from:

http://cgi.ebay.com/ebaymotors/1999...Q5fTruckQ5fPartsQ5fAccessories#ht_2563wt_1046

Supposedly remanufactured, tested, updated, and they code in the VIN and mileage for my vehicle, so all I have to do is install it.

So ATOT, does this seem like a good plan?

 

[LTC8K6]

Check the whole evap system. Canister, lines, valves, wiring, etc.


P0443 (M)
Evaporative Emission Control System Purge Control Valve Circuit
An open or shorted condition detected in the EVAP purge solenoid control circuit. Check the charcoal canister for fuel saturation. If the vehicle has been overfueled, then there is a chance that liquid fuel can enter the canister and cause drive problems or emission related problems.

 

[LTC8K6]

Check the electrical connectors for corrosion. Clean them anyway to see if it helps.

 

[mvbighead]

Check the whole evap system. Canister, lines, valves, wiring, etc.


P0443 (M)
Evaporative Emission Control System Purge Control Valve Circuit
An open or shorted condition detected in the EVAP purge solenoid control circuit. Check the charcoal canister for fuel saturation. If the vehicle has been overfueled, then there is a chance that liquid fuel can enter the canister and cause drive problems or emission related problems.

As far as I remember, the mechanic did all that at one point and said everything looked good. Each time I have looked at the hoses and what not, I haven't seen an issue. Will take a look again and see what is there.

 

[mvbighead]

Check the electrical connectors for corrosion. Clean them anyway to see if it helps.

I plan on doing that this evening. Thanks for the input.

Assuming the wiring and connections look good, the ECM would be the next logical step... right?

 

[LTC8K6]

That seems to be the web consensus. Hopefully you don't need to go there.

 

[allanon1965]

Assuming the wiring and connections look good, the ECM would be the next logical step... right?


NO! There are tests to determine the fault. when the fault code is set, you need to use a capable scanner the can show freeze frame data and mode6 data. How can you expect to fix it by throwing parts at it?

Ideally a DRBIII would be the best choice, but unless you take it to a dealer or a shop that is tooled with dealer scanners that is not gonna happen, so the next best bet is to take it to a shop that is competent on emission repairs.

I would never buy a reman ECM froom ebay...ever! I have seen way too many that were "coded" and would not even let the damn car start! I would be willing to bet that there is a connection issue with the wiring or connectors, you need to look not only for corrosion, but also do a drag test on each and every pin in all the connectors in that circuit. Over time the connectors will loosen and cause intermittent issues, which is exactly what your situation sounds like.

Dont throw more parts at it until all of the basics have been checked and double checked. Just because you replaced the solenoid doesnt mean it cant fail again. I only use OE parts for emission failures. did you use an OE solenoid or an aftermarket junk one?

 

[5150MyU]

Gotta agree with allanon1965 and a refailed solenoid is not out of the question.

 

[mvbighead]

Assuming the wiring and connections look good, the ECM would be the next logical step... right?


NO! There are tests to determine the fault. when the fault code is set, you need to use a capable scanner the can show freeze frame data and mode6 data. How can you expect to fix it by throwing parts at it?

Ideally a DRBIII would be the best choice, but unless you take it to a dealer or a shop that is tooled with dealer scanners that is not gonna happen, so the next best bet is to take it to a shop that is competent on emission repairs.

I would never buy a reman ECM froom ebay...ever! I have seen way too many that were "coded" and would not even let the damn car start! I would be willing to bet that there is a connection issue with the wiring or connectors, you need to look not only for corrosion, but also do a drag test on each and every pin in all the connectors in that circuit. Over time the connectors will loosen and cause intermittent issues, which is exactly what your situation sounds like.

Dont throw more parts at it until all of the basics have been checked and double checked. Just because you replaced the solenoid doesnt mean it cant fail again. I only use OE parts for emission failures. did you use an OE solenoid or an aftermarket junk one?

Purchased the replacement solenoid from MoparWholesale.com, so it should be OE. At this point, I have checked the cabling to the best of my ability, and haven't seen much, everything looks good and clean. Rather than give it a new ECM, I figure I'll probably just drop it at a shop and let them deal with it. Seems to be a bit beyond my capabilities.

EDIT: The only other issue which I failed to mention before is that as long as I've had this vehicle, it has always had a rough idle. Not anything too rough mind you, but it doesn't sit happily at 600, and seems to bounce between 550 and 650 and sometimes dips down to 500. From what I've read, this could be symptomatic of the evap system causing too lean of a fuel condition. I have always had this problem, even after initially changing the solenoid. My mechanic had checked the solenoid after something else I had brought it in for, and determined it was in good shape. I am guessing this will be the same next time I bring it in, but could be wrong.

I'd rather not bring this car to a dealer, but if my mechanic is unable to determine what is going on with it, I believe that might have to be the path I take.

EDIT #2: Looks like my scanner can do FreezeFrame, but not Mode 6. Innova 3100 is the model. http://www.amazon.com/gp/product/B000EVWDAK If I had a higher model, what additional information would that give me?

 

[LTC8K6]

http://www.wjjeeps.com/service/tbody.htm

Maybe try cleaning the TB and IAC valve?

 

[LTC8K6]

http://www.wjjeeps.com/tsb/tsb_wj_183598.pdf

Not for your MY, but interesting.

 

[mvbighead]

http://www.wjjeeps.com/service/tbody.htm

Maybe try cleaning the TB and IAC valve?

I did just clean the IAC actually. Didn't do anything with the TB as it seemed clean, though I suppose I should clean it regardless.

Thanks for that link though. I had read several different ways to clean the throttle body (this one included), and when I got in there, was second guessing which way to go about it. I will probably do this tonight if I remember, as I have two full cans of throttle body cleaner... so I just was well do it anyway.

 

[allanon1965]

with a better scanner, at least as capable as the factory DRBIII you can actually run the evap tests and check for proper voltages at the connections and confirm proper operation of the evap system. I dont know if any scanners other than the DRBIII and snap-on scanners and otc scanners that allow that function...

 

[mvbighead]

Assuming the wiring and connections look good, the ECM would be the next logical step... right?


NO! There are tests to determine the fault. when the fault code is set, you need to use a capable scanner the can show freeze frame data and mode6 data. How can you expect to fix it by throwing parts at it?

Ideally a DRBIII would be the best choice, but unless you take it to a dealer or a shop that is tooled with dealer scanners that is not gonna happen, so the next best bet is to take it to a shop that is competent on emission repairs.

I would never buy a reman ECM froom ebay...ever! I have seen way too many that were "coded" and would not even let the damn car start! I would be willing to bet that there is a connection issue with the wiring or connectors, you need to look not only for corrosion, but also do a drag test on each and every pin in all the connectors in that circuit. Over time the connectors will loosen and cause intermittent issues, which is exactly what your situation sounds like.

Dont throw more parts at it until all of the basics have been checked and double checked. Just because you replaced the solenoid doesnt mean it cant fail again. I only use OE parts for emission failures. did you use an OE solenoid or an aftermarket junk one?

Well... wrong, wrong, wrong.

I am probably responding to this as I am a little pissed out how awful the dealership did with quoting their service. $99 diagnostic that turned into $300 before any repairs were done, but whatever. At any rate, dealership advised that the solenoid was bad again, which I emphatically emphasized that it was replaced 3 months, but decided to tell myself that it could be bad again.

4 hours after receiving the vehicle, a subsequent startup revealed the same, exact idle issue and check engine code. Bring it back in to dealership, super pissed, and they promise to check out it again...

This time, within a matter of no more than an hour, they come back with the same diagnosis as my previous mechanic... a bad ECM. A bad, $762 ECM.

At this point, I am between ordering an ECM from ebay for about $250, ordering an ECM for moparwholesale.com for $360ish+shipping, buying an ECM from my mechanic for $400.... and that's about it.

Guess I brought it to a dealer mechanic thinking their special DRBIII tool would tell them up front and forward what the problem was... when in fact, I should've just trusted my mechanic in the first place and brought it back to him.

My only frustration with your post is that it completely ignored my mechanic's diagnosis, and that, for some reason, I felt you might be right about the whole DRBIII business... well, turns out, my mechanic had it all figured out, and had me pointed in the right direction from square one. Never again will I trust that dealership for any repairs. Their first order of business was to do exactly what I did in a matter of one hour to diagnose and repair with a $30 part, vs their $397 invoice for their work... that caused an additional trip to the dealer, and the original diagnosis that my (real) mechanic had already come up with.

 

[kornphlake]

There is another option: do nothing. If the solenoid is operating correctly and the ECU is incorrectly reporting it's function then there's no reason to stop driving the vehicle. You aren't polluting any more than you would if the ECU was reporting the correct operation. This error shouldn't adjust the fuel trims or anything else that would cause the engine to run rough or otherwise improperly. The only reason I see to spend good money to fix this glitch is if you have state emissions that demand you repair the problem to pass emissions (you can often sneak by if you clear all codes a day or two before going in to have the emissions test done, typically it takes longer than that for the code to be set, the CEL may come on the day after the emissions test but the state doesn't know that) or if you are selling the vehicle and don't want to loose money on reasle because of an obvious fault.

 

[LTC8K6]

ECM Seems to be under $300 at Rock Auto.

 

[mvbighead]

There is another option: do nothing. If the solenoid is operating correctly and the ECU is incorrectly reporting it's function then there's no reason to stop driving the vehicle. You aren't polluting any more than you would if the ECU was reporting the correct operation. This error shouldn't adjust the fuel trims or anything else that would cause the engine to run rough or otherwise improperly. The only reason I see to spend good money to fix this glitch is if you have state emissions that demand you repair the problem to pass emissions (you can often sneak by if you clear all codes a day or two before going in to have the emissions test done, typically it takes longer than that for the code to be set, the CEL may come on the day after the emissions test but the state doesn't know that) or if you are selling the vehicle and don't want to loose money on reasle because of an obvious fault.

Problem is, the ECU is causing a malfunction. The car dies at times and struggles to maintain idle.

 

[mvbighead]

ECM Seems to be under $300 at Rock Auto.

I should've given them a look as well, but I have now committed to having my mechanic fix the problem now. Looks like what I am seeing on Rock is the service to have it rebuilt or something like that. That would've left me without a vehicle until receival of the new part, which would've been a major drawback. At this point, I can drive the vehicle as I wait for the mechanic to receive the re-manufactured part that is pre-coded by his parts provider.

At this point, I just want to be done with it and to have the service be someone else's problem if this isn't the final solution for the dreaded P0443. My mechanic will warranty the part and the work for a good time period (I believe 1 yr.), so if I can get this done and be happy, I'll be set. And, it's a bit more than $300 cheaper than what the dealer is telling me. I just hope this is the final fix.

 

[5150MyU]

Wish you luck-Make the headache go away and be done with it.
Sounds like you have a good mechanic-stick with him and say you're sorry for second guessing him

Stealerships can be really iffy, they give the job to someone that barely understands electronics/electricity, and the guy that does never even knows about the vehicle.

 

[mvbighead]

Wish you luck-Make the headache go away and be done with it.
Sounds like you have a good mechanic-stick with him and say you're sorry for second guessing him

Stealerships can be really iffy, they give the job to someone that barely understands electronics/electricity, and the guy that does never even knows about the vehicle.

Much appreciated sir. I did actually end up doing okay in working the whole deal out. I ended up talking to the dealership and essentially playing the part of the pissed off customer (which I indeed was) to the point of the $100 diagnostic that turned into $300. Kept at it enough, now they're sending me a $120 check. Granted, it ain't the whole $200 difference, but I figure they could wrap some of that up into the solenoid repair and follow-up checkup.

And, as for my mechanic, after much debate on whether to order a remanufactured ECM from ebay (all of which the sellers had 99.9+% positive feedback) I decided to pay the extra $150 or so and stick with my mechanic. I had actually discussed the repair with him, and initially suggested that I'd probably just order one myself... but then changed my mind as I wanted to have the peace of mind that the repair work would be warrantied and I would be done with it all. I know my mechanic appreciates the business, and they're always a good group of guys to talk to about car problems. Any major car emergencies, and they're willing and able to take an immediate look at it to get me back on the road.

Well, hopefully he gets the ECM in today so I can drop it off tomorrow and be done with it.

 

[rklausing]

just read your post, I have the same exact problem with my 4.7 2000 jeep grand cherokee. Question was the ECM the final solution for the 0443 problem? I seem to be headed down the same road.

 

[jrios38]

I have tge same problem with the samee jeep 4.7 . If you checked everything else concerning the code 0443 it is most likely that it is the ecm!! At the moment iam trying to find out were to buy a reliable one at pocket friendly price.. Dnt order online with auto computer exchange they have a lot of complaints against them i was about to when i read there reviews it made me think twice!!

 

[manimal]

I have tge same problem with the samee jeep 4.7 . If you checked everything else concerning the code 0443 it is most likely that it is the ecm!! At the moment iam trying to find out were to buy a reliable one at pocket friendly price.. Dnt order online with auto computer exchange they have a lot of complaints against them i was about to when i read there reviews it made me think twice!!

Welcome to AT and the garage!!

We dont mind introduction threads with picts of cars too!!

Have you checked car-part.com for a local pull? I got a ecm for a Junky breeze my nanny has been driving for 65 bucks.

 

[LakeTime]

I've got the dreaded "P0443 Keeps Returning" on my 99 JGC 4.7, and this thread has been a bunch of help to me. I'm trying to drill down on my own to the source, so let me share what I'm finding and maybe someone can help me.

Hoses and lines to and from the Purge Control Solenoid, the intake, and the charcoal canister are fine - no splits, cracks, holes.

The solenoid itself seems to be working fine - I tried to get it to move/click using a 9 volt battery across the contact pins (has worked well for me to check most other solenoids/relays) and it did NOT, but it did move/click fine with 12V battery power, and I used a section of tubing to blow through the ports when clicking to verify its clear and working properly.

I tried to check voltages at the connector (while disconnected), and got what I think are weird results. My understanding is that, when the key is on or engine started, you should get battery voltage (my battery was at around 12.4V today) on one side of the connector (connector to body ground), and I would ASSUME 0V on the other side - I understand this to be a ground, switched through the ECM... Is this a correct assumption?

But... With the key just ON, I get just 8.5V on the hot side of the connector (not enough to energize the solenoid/overcome the spring, from my 9V battery experiment) and 5V on the ground side!!!! Should I be getting ANY voltage from the ground side??

With the engine started, I do get battery voltage (well, alternator voltage - 13.8V) on the hot side of the connector, but I STILL get 5V on the ground side...

Is the ECM trying to tell me something? Down for the count?

Another sort of weird symptom... If I turn the key from OFF to START real quickly, I can often/usually avoid the CEL tripping right away with the P0443 code. But, if I turn it to ON, let the fuel pump prime the rail, and then go to START, the CEL trips to P0443 all the time/almost all the time. I'm wondering if, since it’s only getting 8.5V while ON, the delay is enough for the ECM to read the voltage, not find full battery voltage, and trip the light. Conversely, turning it to START fast gets the engine turning and full battery voltage quicker, helping to avoid the CEL. Make any sense?

Net, can anyone help me? Should I be getting ANY voltage on the ground side of the connector??? Is any of this indicating that the ECM is the source of my problems? Anything else I can do to verify? Thanks for ANY help you can provide....