I need a new/rebuilt ECM--where to look?

Hey guys, I have lost the 3-4 shift signal and I traced it back to the ECM. At P52 and P57 I only have .18VDC and I have a burnt capacitor on the ECM board. The bad cap may not be the cause of the loss of the 3-4 shift but it tells me there is issues. Where should I look for a rebuild? I found a place on the web but they want $249. Is there a place in Florida that works on them and what should I expect to pay?
Thanks

Pick and pull or a junkyard.

eBay is a great place. Good luck

Ebay, yes, I bought a spare 98 302 PCM for $50. Good luck,

Ask me....

I have one I would let go for $50.00 Send me a PM if your interested.

Thanks Rob

CDW6212R said:

Ebay, yes, I bought a spare 98 302 PCM for $50. Good luck,

Click to expand...

I think mine was $10.99

The PCM provides a ground to activate the solenoid as I recall, not +12V. Before you go replacing it check all your grounds.... If Mr. Shorty reads this he can pipe in with cogent info. (Now a ground is ALSO not .18v, I admit - and you might be on the right track... yet .18v DOES sound like a floating voltage, looking for a ground). Failing him showing up you might PM him. He is the site expert of electrical issues of this sort. He is the guy *I* go to.

In Ford computers, there is a "true ground", which is (-), and then there is a sensor ground, which is a little bit off of that, with a small deviation in the (+) direction. I once had that problem with the wiring on the power steering pressure switch. When I shorted the sensor's ground wire to a true ground, the check engine light went off. It is probably controlled by a resistor divider network inside the PCM. Autozone sells remanufactured ECMs made by Cardone. In my past experience, I've had no luck emailing their company. Here is the information on their website with contact information: CARDONE Industries USA
Corporate Headquarters • 5501 Whitaker Avenue • Philadelphia, PA 19124-1799
Phone: 215-912-3000 • Fax: 215-912-3700

I found this link:

http://car-computers.com/index.html

-Drew

Does anyone know the part number for a 98 build SOHC PCM? Ford UK want $1600 for one so I was going to look on ebay but I need to know the part number and in the UK Ford use different part numbers. Please help!

Andy, the part numbers for all Ford PCM's will have the same base number, the middle section. The other numbers, 1st and last, both signify the vehicle type, model year, engine, and calibration.

Unless there is something odd about the PCM of a non US Ford, you should be able to use any PCM from a SOHC Explorer/Mountaineer from 1999 to 2001, and very possibly the 2002+ Sport Trac and Sport models(same body size).

Why do you need a new/used PCM? The 98+ Fords have PCM's which are married to an anti theft module, called PATS in those years. If you replace either then they will have to be reprogrammed together. Meaning that a Ford dealership tool is required to install those two modules. You can swap the modules, but the engine will not start until the modules are programmed together.

If you do need one, I would simply buy a 99-01 model 4.0 SOHC Explorer PCM, and take it with the truck to a dealership. A used PCM should not cost more than about $75 here, I bought a spare 98 V8 PCM two years ago for $50 on eBay.

The PCM can be swapped in a few minutes, I don't know how long the reprogramming would take. Good luck,

I have a poor idle with codes relating to too lean and too rich on both banks and both O2 sensors detecting both banks lean. I have had a new MAF, TPS and inlet manifold gaskets. A Ford dealer also confirmed there are no leaks and a cylinder compression test was fine, they recommended that it was almost certainly the PCM.

One thing to remember is when you swap the pcm your vehicle will not start due to the interference of the PATS system. There are two ways to eliminate this.
1st) Tow vehicle to dealer and have the PATS programmed after the new pcm installation or
2nd) Purchase an ExCal2 which can turn PATS off and not only this you will have custom tuning to boot.
Contact me if interested in the ExCal2.

andypalmer said:

I have a poor idle with codes relating to too lean and too rich on both banks and both O2 sensors detecting both banks lean. I have had a new MAF, TPS and inlet manifold gaskets. A Ford dealer also confirmed there are no leaks and a cylinder compression test was fine, they recommended that it was almost certainly the PCM.

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This can also be something as simple as a vac leak in the brake booster,bad vac lines,leak in the inlet tubing between the maf meter and throttle body,throttle body gaskets,etc. Before swapping a computer I would definately determine the source of the problem. I don't believe you have a computer problem.

The main thing that leads me to believe my local Ford dealer is that I was also advised this is likely by another garage. Also, Ford had the vehicle for 3 days and could not find anything mechanically wrong with the engine which point towards PCM or sensors. The other garage are LPG conversion specialists and I spoke to them as my vehicle is converted to run on LPG due to its cost in the UK relative to petrol.

They advised me they have seen quite a few Explorers that have been LPG converted with this problem, almost always due to the PCM. They claim that the PCM does a test every 60 days and that if it is running on LPG at the time of these tests, due to the different burn characteristics, the PCM can rewrite its base parameters. They advised that these need to be rewritten back to factory parameters but Ford UK will not support this as they can make more money by selling a new PCM. I have found a few places that may be able to remap the PCM but this is to gain performance which is not what I am looking for. Does this sound like something the PCM could do? I understand its basic job but not all the features.

On a different note would this ExCal then mean the immobiliser/remote unlocking is inoperational?

Thanks.

That's a hard one Andy. I don't know enough about the OBDII PCM and how it can work with LPG. I would have thought that a reprogrammed PCM would be required as part of the conversion to LPG. I know that LPG is best used with much higher engine compressions, like 15:1, and the SOHC is in the mid range for a gasoline engine. A static compression ratio of 8:1 would be low, and over 10:1 is high for gas engines today. What I'm hinting at is that the best air/fuel ratio is different for LPG versus gasoline use, and the compression ratio is also part of the equation. That is why LPG conversions are rare, the best conversion requires higher compression, a much different rebuilt engine.

I agree with James, I don't believe that the PCM is defective in your truck. The O2 sensors are used to determine what the A/F ratio is, and the PCM does a fine job of obtaining the programmed A/F ratios for various conditions.

If you have a stock programming PCM, then I think a better program would be the first thing to obtain. The stock PCM will not be running the engine for best LPG efficiency, it will be trying to adjust the fuel to obtain the best gasoline A/F ratios.

Do some research into LPG conversions, specifically related to needed air/fuel ratios. Try to find a source for programmers who can build you an LPG program for your PCM. The Xcal2 is the current best PCM programmer device, also called a flasher, and made by SCT. You can buy them from many sources for $350ish new. The key is the person who installs the programming into it, which can be sent by email. Consult with Doug of http://bamachips.com/ to see if he has heard of any special programming for LPG engines. Good luck,

The LPG system does not have its own PCM and is not controlled by a PCM at all. There is one box which cuts off the injectors and loops a good signal from the injectors back to the PCM. The LPG is then supplied into the air pipe just after the IAT sensor. The amount supplied is based on airflow, it is basically sucked in by the air passing across the end of the connection, ie more air, more LPG. Until September last year this was working fine with a perfect idle, despite the kit having been on there for 5 years. Also the problem occurs on petrol as well as LPG, I ran the truck for 2 weeks just on petrol and it made no difference. Because of this I have pretty much ruled out anything to do with the LPG system. This is set up to run the same on LPG as it does on petrol so a problem on petrol will be replicated on LPG. When it was running fine it felt exactly the same on LPG as on petrol.

If I decided to try a PCM would you advise a used (with 30 day warranty) or reconditionned PCM? I found this 1999 one that I was thinking of trying as it is reasonably cheap. http://cgi.ebay.com/ebaymotors/ws/e...RK:MEWA:IT&viewitem=&item=280112341895&rd=1,1

I see, the LPG use is about tricking the PCM with injector signals. Then the actual A/F ratio is determined by the conversion parts, I had not been exposed to the details of such a system before. It leaves a lot of possibility for less than ideal A/F ratios for various conditions, very much like a carburetor. It sounds like the original design has worked very well, that's good. It is possible that the O2 sensors cats, or even other sensors have deteriorated over time, which happens with or without gasoline being used.

I would still doubt the PCM to be the problem, although I recognize that the PCM has very little control when LPG is used. That it works with gasoline does suggest that the PCM is okay. Generally a PCM doesn't fail partially, they usually will fail completely, or the symptoms will be very large.

If you do still want to try another PCM, know that basically they either work or not. An old or high mileage PCM is almost equally likely to be good or bad, compared to a low mileage PCM. New PCM's used to be just over $200 some years ago. They are more now I'm sure, but to get a used PCM for under $75 is a good deal. The reputation of the seller is more important than the vehicle mileage of the PCM. Good luck,

Just to clarify, all the same faults are present regardless of fuel used at the time. Thanks for your help and advice.

jah81592 said:

One thing to remember is when you swap the pcm your vehicle will not start due to the interference of the PATS system. There are two ways to eliminate this.
1st) Tow vehicle to dealer and have the PATS programmed after the new pcm installation or
2nd) Purchase an ExCal2 which can turn PATS off and not only this you will have custom tuning to boot.
Contact me if interested in the ExCal2.

Click to expand...

What does PATS consist of? I don't really want to lose the alarm and immobiliser as it would invalidate my insurance.