**Lincoln LS - PCM Interchangeability**

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ac_2007

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Hey fellas,

My family member's 2001 Lincoln LS V8 has been diagnosed as having a faulty PCM, causing a misfire on Bank 2 (Cyl 7)

Our indy mechanic has all of the Ford / Lincoln diagnostic and programming tools as his disposal.
Question is, could a donor PCM from a 2000 Lincoln LS V6 be reprogrammed to work with our V8?

I'm guessing once the VIN is entered into the software, the appropriate maps & data will be loaded onto the new PCM?
Someone please correct me if I'm wrong.
 
No, the V6 PCM does not have the correct IO (hardware) for the V8.
 
joegr said:
No, the V6 PCM does not have the correct IO (hardware) for the V8.
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Darn.. well I paid $48 for a door lock actuator and the PCM. Guess that's not too big of a loss.

LSFrank said:
How many coils have been replaced?
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All have been replaced a couple years ago. As have both VCGs. They're fine - I started the car with each COP out of the cylinder, and a spark plug on it. All provided spark.

Fuel injector on Cyl. 7 is getting no pulse. :(
 
How old are plugs and what is the gap? What brand of coil? Failing coils still are capable of spark, though it can be too weak to ignite the fuel mixture, and it can happen only at certain RPM ranges, with certain loads on the engine. I'm not sure about why the injector won't cycle though, how are you measuring the (lack of) pulse and what do you see when the other injectors cycle? What codes are you getting if any? I don't know if the PCM is capable of disabling the injector in the case of a misfire. Could still be bad PCM but your test likely didn't rule out bad coils either.
 
ac_2007 said:
... I started the car with each COP out of the cylinder, and a spark plug on it. All provided spark.

Fuel injector on Cyl. 7 is getting no pulse. :(
Click to expand...

You can't test them that way. They become marginal, rather than fail completely. The only way they can be tested is to stress test them while scoping the ignition. It costs as much to do this as it does to just replace them.
 
Sadly, it is not the coilpacks or spark plugs. I've got a box full of known good (OE / and aftermarket) COPs that I've amassed over the years.
Tried at least a half dozen of them, and replaced the Cyl 7 spark plug for my own curiousity with a brand new MotorCraft plug.

No dice.

The indy's diagnostic equipment verified no signal at all to Cyl. 7 injector.
I'm sure if I stood outside with a mutimeter and compared the signals, I would come to the same conclusion.


This car's PCM has been previously replaced twice (under warranty), and has previously caused the same issue.
There is no doubt in my mind the same scenario is playing out.

I just needed to know if the V6 PCM could be coded to mate with the V8. I guess not, too bad, so sad.
Another trip to the junkyard is in order I suppose.
 
I would agree that there is a 100% chance that you do not have a failed or even marginally failed coilpack...
 
What is so hard about calling them the correct name, or even just calling them coils?
 
ac_2007 said:
Sadly, it is not the coilpacks or spark plugs. I've got a box full of known good (OE / and aftermarket) COPs that I've amassed over the years.
Tried at least a half dozen of them, and replaced the Cyl 7 spark plug for my own curiousity with a brand new MotorCraft plug.

No dice.

The indy's diagnostic equipment verified no signal at all to Cyl. 7 injector.
I'm sure if I stood outside with a mutimeter and compared the signals, I would come to the same conclusion.


This car's PCM has been previously replaced twice (under warranty), and has previously caused the same issue.
There is no doubt in my mind the same scenario is playing out.

I just needed to know if the V6 PCM could be coded to mate with the V8. I guess not, too bad, so sad.
Another trip to the junkyard is in order I suppose.
Click to expand...

So you only changed 6 coils top, hopefully all at once. That still leaves 25% uknown assuming your stash was 100% good...

Did you see the waveform on the oscilloscope while stress testing the coils? What did the waveform look like? This is the only way to have a known good. The odds of failure on a motorcraft brand new coil are low enough that most of us just blindly install it, but even a new motorcraft coil could be bad and a stress test/waveform view is the only way to be 100% sure its good. There is no such thing as a good "oe aftermarket" or ebay coil. We have a large data set of people including myself that try to get out on the cheap: there's a reason we say spend the money and replace them all with new motorcrafts from Ford. A brand new Accel might be the only aftermarket exception.

You replaced a spark plug... what was the old and new gap? How many miles on the coils and plugs? They're so cheap, just do them all. Gap them to 1mm/.039".

You can use the same scope to look at the injector in question. Look for damage to the wiring as far back as you can see. Check the wires for short to ground or each other.

It sounds like you either have a wiring problem, such as corrosion just as one example, which is destroying PCMs or interference from bad coils or even discharging very high voltage into bad places (coil still fires/discharges but doesn't light the spark in the cylinder). You should not be going through PCM's like candy. Perhaps its getting wet? Have you examined the old one when it comes out?

We ask specific questions because your diagnosis and test procedures are not robust. You may in fact have the right conclusion about the PCM but you arrived from the wrong/ inadequate testing. We are attempting to help in a more methodical manner, starting with most common issues and working backward while also having regard for your time and wallet. We as enthusiasts of this specific car know the trickery this car is capable of when it comes to diagnosing these problems and the Ford way has proven to not always be the best. Case in point, your own; they fix the effect but not the cause.
 
I agree that blowing PCMs is indicative of bigger problems / wiring issues. If its of any relevance, the car also experiences random flashing of the battery light, AdvanceTrac light, and has also now gone through a second clockspring (causing intermittent airbag lights as well).

The car has nearly 320k KM, and (sadly) is hardly worth more than the tires it sits on. If we can cheaply get another 50k out of it, that'd be great.

Shame, since the body / mechanical is 100%
 
Its very relevant. How old is the battery and alternator? You might want to replace them both then see if your "problems" still exist. If one is in fact needed, make sure it has a vent tube and vent to exterior. A bad alternator can ruin a new battery so age alone does not say if its good. Is the alternator original? Do you get a check charging light sometimes? What is voltage with key off, during starting, and with engine running? The computers are very picky about voltage/power and any noise/interference. And don't consider it a waste if you spend the money and this doesn't fix it, all of these things should be done anyway. It sounds like you have many issues that could be contributing factors to your problems.
 
02LincLS said:
Its very relevant. How old is the battery and alternator? You might want to replace them both then see if your "problems" still exist. If one is in fact needed, make sure it has a vent tube and vent to exterior. A bad alternator can ruin a new battery so age alone does not say if its good. Is the alternator original? Do you get a check charging light sometimes? What is voltage with key off, during starting, and with engine running? The computers are very picky about voltage/power and any noise/interference. And don't consider it a waste if you spend the money and this doesn't fix it, all of these things should be done anyway. It sounds like you have many issues that could be contributing factors to your problems.
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The diodes in the alternator have been failing. The flickering battery light has been going on for the past 2 years. ~14.2-14.3v while running. No voltage / amperage drop when the light comes on.

"Check AdvanceTrac", I don't know. I suppose it could be a by-product of the alternator issues. Or another electrical gremlin. It still works perfectly fine.

The car looks mint inside and out. You could pass it as having 50k miles. These are just trivial issues I haven't felt the need to address.




SO... back to the original question. Is the V6 PCM not compatible with the V8 because of a different board inside? Are the harness connections obviously different? I haven't yet removed the V8 PCM so I didn't get a chance to compare.
 
ac_2007 said:
The diodes in the alternator have been failing. The flickering battery light has been going on for the past 2 years.

These are just trivial issues I haven't felt the need to address.
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so instead of a health DC voltage that the electronics are designed to work with, you alt has been leaking AC current into the system that has a tendency to destroy computers... doesn't sound trivial at all, no wonder why you need a new one... or even why you have had to have so many of them...



ac_2007 said:
SO... back to the original question. Is the V6 PCM not compatible with the V8 because of a different board inside? Are the harness connections obviously different? I haven't yet removed the V8 PCM so I didn't get a chance to compare.
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that is exactly what Joe said, it doesn't not have the correct I/O, so yes the board is different (as he said HARDWARE and not software...) the harness connections could very well be the same but the V6 would just not be using all of the pins in the harness, as in the PCM doesn't have those pins internally since it wasn't designed to control two extra cylinders... they again, it could have completely different connectors just to keep people from trying to do stupid things....
 
So just thought I'd update the thread. Ever since the PCM was swapped (with an appropriate V8 one), the engine still ticked on cylinder 7.

Cyl. 7 maintained and then lost compression, likely due to a chipped / cracked valve. I told myself I'd drive this car into the ground and so I did.. ticking away.

Unfortunately today while driving to work, she finally had it and the valve dropped. The engine died out and I had to pull over to the shoulder. I carefully tried idling it to a safer portion of the road, as pressing the gas pedal would simply stall it out.

If you are located in the Toronto area and need any parts, shoot me a PM! She'll be scrapped in a week.


RIP - 08/06/2015 @ 316,000km
 
Well, at least its suffering is over now...
 
all I picture is a slow fading LS montage and a Sarah Mclachlan song playing...
 
ac_2007 said:
So just thought I'd update the thread ...

If you are located in the Toronto area and need any parts, shoot me a PM! She'll be scrapped in a week.

RIP - 08/06/2015 @ 316,000km
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Say .... is this Jason from the TO area with the white LS listed on Kijiji, the one that kept me waiting from 1AM to 5:30AM for all the rear tail lamps and then texted me that you didn't know we meant that day to meet at the Fn coffee shop?

Was that you?

If that wasn't you, I'd be interested in all the rear tail lamps off that 1st GEN if they are in perfect condition and you can meet me near the airport on Dixie some day/night.
 
Anyone know if the mtx ls's use a different pcm than the automatics? I may need a new pcm for my 01 v6 mtx ls. Was hoping I could maybe pick ac2007's if it's compatible. That's for any info
 
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