I have a lo mileage 94 E 150 van (104,000 miles) (5.8L, A/C, auto) but this may apply to all 94 Fords. AAMCO recently put in a new transmission. After about 2 weeks, the vehicle began to go into "creep" or "safe" mode intermittently. The local Houston Ford dealers refuse to work on it---that's right---REFUSE TO WORK ON IT !! They claim they don't have the breakout boxes to check out the PCM and they can't get the PCM to communicate with them. Some independents have told me that that is a lot of baloney---they just don't WANT to work on it.

We sent in a complaint form to FoMoCo and essentially they told us to bug off.

With my check engine light, I can get codes. First code I get for the KOEO is system pass, then a 512 code---keep alive memory failure. What does the 512 code mean---is that why Ford says they can't communicate with the PCM.?? Does this mean the PCM is failed?

What causes the PCM to go to to this safe mode ? I understand safe mode is 2nd and 3rd forward gears and reverse available and NO fuel mixture calculations....full rich fuel.

I am really stuck. Help would be appreciated. IT IS THE LAST FORD I WILL EVER BUY with service treatment like this.

 

Are you sure that the trans shop did not:
-break a vacume line?
-break an wiring conector?
-sell you a sick trans?
[these is my guesses if the van worked fine until the trans broke,
but then I don't do automatics]

I have experianced limp home mode due to a design flaw in a vw van, but the problem existed since it was new.
[and vw customer relations is worse than fords by a mile.
if it costs to much to honor the warentee, they don't,
knowing most people don't sue]
In this case I needed the vw part "engine missfiring wiring harness", which was a $500 fix for a defect that VW would not admit to having made to all US 91 vanagons.

Back to Ford:
I think that you need a ASE master with a computer to find out what is going on.
If it was the trans shop, you need something in writing.
You can probibly find this mechanic at your local ford dealers competition, the next closest ford dealer.
David

 

From the Ford shop manual:

Continuous Memory DTC 512 indicates the PCM has experienced a power interrupt in its Keep Alive Memory (KAM) circuit.

NOTE:
If KAPWR is interrupted to the PCM, for example when installing a breakout box, or when battery is disconnected, DTC 512 may be stored in Continuous Memory.

Key off.
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, leave PCM disconnected.
Measure voltage between Test Pin 1 and Test Pin 40 or 60 at the breakout box.
While observing DVOM, grasp the EEC-IV harness and wiggle, shake or bend a small section while working from the PCM to the dash panel.
Does DVOM indicate less than 10.5 volts?

Click here for a wiring diagram of the 1994 PCM KLM.

In other words you are losing power to pin one of the PCM. Check your wiring to pin one of the PCM.

 

Thanks for the info. I have verified 12 v going to pin 1 at the connector and have checked it in the PCM. There is a 100 ohm 1watt resistor on the pcm board and the 12v from the battery is dropped across that resistor. 12vdc is seen at the resistor. Now one thing I have not checked is the PCM ground connection. If the PCM ground at pin 40 is intermittently dropping out, would the pcm not recover once ground is restored and put the vehicle in safe mode. BTW, I have the electrical wiring diagram for the 94 e150 and it has been helpful. Do any of you folks have the book with the info on the pcm itself. I would really like to know if intermittent individual sensor input loss will cause the PCM to drop the vehicle into safe mode and if so, what sensors are they.
Again, thanks a bunch for your help. I have felt absolutely ditched (and helpless )by FOMOCO. Bill G.

 

David, thanks for your input. The independents are saying they dont have the required breakout boxes and I should take the car to the Ford dealers. Then, one Ford dealer recommended a Ford driveability tech expert at a dealership 100 miles from here. I called that dealership with about two questions to ask this "expert" and they told me he wasn't allowed to talk over the phone. I am 67 years old and I feel my blood pressure rising as I write this, so I better quit. Again thanks for your response and help.

Bill G.

 

Make sure you have a good ground at G101(Left side of engine compartment, near battery).
If so I think I would go ahead and change the PCM as I do not know of any thing else out side the PCM to cause this.
I do have a breakout box but if you verified pin 1 with power the breakout box is not going to help any as that is all it was for.

 

> AAMCO recently put in a new transmission.

I guess the local dealers feel the need to punish you for that action by not helping you and lying to you.

> I called that dealership with about two questions to ask this "expert" and they told
> me he wasn't allowed to talk over the phone.

Plus, he probably does not WANT to talk on the phone. The expert does not earn money for his family giving free advice on the phone to people that had their transmission repaired elsewhere, especially when he is already losing money working flat rate on Ford warranty claims.

I suggest when it comes time to buy a new vehicle or parts, remember how you were lied to and treated, and don't even buy a windshield wiper at those dealerships that treated you that way.

In the FWIW department, when encountering any bad CPu/ECM/PCM that you are going to have to replace at full cost without a core charge, it is always worth it to disassembly it and replace the caps and resistors that are not wave soldered to to check the wire harness itself and resolder the board connectors.

 

REBOCARDO;
Thanks for your reply. As I said in my first post, I will NEVER buy another Ford product as long as I live, and I am spreading the word to all I know over the way they have treated me and my wife.Two dealerships would not help, another said well, maybe in 3 weeks but meanwhile, take it to SNIDER transmission.
RE; the PCM board, there were three electrolytics on it one of which had goo coming out of its base. I replaced all 3 electrolytics but I still get the 512 code.I could not resolder the board because it was coated. The only way I could solder in the replaced electrolytics was by soldering to the leads of the old capacitors that protruded through the coating on the board. There were also a bunch of tantalums in there but I was afraid the leads protruding through would not be long enough. Again, thanks for your help.

 

SUBFORD
Thanks for the input. I will check that ground. I was wondering if the pcm reads the transmission mode...ie PNDL or R and if it does and perhaps the transmission mode switch is misaligned or failed and maybe the pcm detects an impossible situation such as L and R at the same time if it will drop the vehicle into safe.

Thanks again.

 

Yes it does read the PNDL or R and the mode switch must be aligned right or you will have shift problems. However I have not heard of or do not think it will cause the PCM go into the limp mode.

In 1994 you have the OBD I PCM and it may be bad but I have not heard of anybody having the error code that you are getting.

There are a lot of fancy code readers out there and some will give scope history readouts. But as far as to communicate with the PCM other than read the codes and clear them I do not think there is any way to do this.

If you think you are having transmission problems why not take it back to AMMCO?

I do not know what a FORD dealer could do for you other than change out the PCM but I have hear these are not available from FORD anymore so they would have to order it from a third party and send in your old one to get it. Then they would have your van for about three weeks until they get the replacement PCM.

 

Bill K.

AAMCO claimed they couldn't communicate with the PCM anymore. Thats why I took it to CHAMPION (? HA !---what a laugh !) FORD and they have given me the big run-around. So, you see, thats where I am. I have gone ahead and ordered a rebuilt pcm from ECUDIRECT on the internet. I plan to install it and run the van around to see if it will stay out of safe mode. If the vehicle goes to safe mode, I guess I will take it to AAMCO and tell them it has a brand new pcm in it and go from there. The thought crossed my mind that I might take it to another AAMCO (other than the one who installed my transmission ) and see what THEY say.

 

> There were also a bunch of tantalums

From experience when these go bad (blue ones) they spew all over the board and wreck it. So, if they look solid they probably are okay.

Had some time and sleep (sorry my previous post was so butchered) so I did a little research on the net and came across a few things. Found a file "ecctech98.pdf".

Looks like to me the memory is one separate chip. Try gluing a small heatsink to it (if the case allows) and see if the problem goes away, the chip itself might be bad.

You might leave off the trim panel and a window open to lessen interior heat and see if that helps the problem disappear. If so, then the memory is probably bad.

 

REBOCARDO

With the engine not running and the PCM removed from its bracket and out under the hood but still connected to the harness, I get the 512 code.BTW, per my previous post on the forum here, I have ordered a new pcm from ECUDIRECT. If all goes well, it should be here early next week. In your research, did you happen to find anything on the logic of the PCM that causes it to put the vehicle into safe mode. I would think a PCM main power loss or loss of return (PCM ground ) would do that but I wonder if there is anything else.
Thanks

 

First, understand that I used to own a couple of AAMCOs. I can tell you that few independant shops of any kind will have the breakout boxes required. There are too many of them and they are too expensive. I would take the vehicle to a good auto electric service. One that does more than just starters/alternators and batteries. Modern auto electric service shops specialize in electrics including PCM diagnostics. They specialize is this kind of work. Check the yellow pages or call some independant shops and ask if they have someone they send their problems to.

Second, my first thought at reading your post is that the installation tech at the Aamco center caught the wiring harness between the engine block and the transmission bellhousing. Its a common problem, easy to do and *can* cause these kinds of mystifying problems. Usually, the tech will catch his mistake and clear the harness, but not always. It may still be caught in there. Pull the doghouse and inspect the harness where it crosses the bellhousing.

I don't understand a dealer that tells you they won't work on it. Its a perfect opportunity to clean up somebody else's mess and demonstrate to you (the customer) that you should have brought the vehicle to them to begin with (for the transmission work). I would call the regional service rep for Ford.

Steve
'95 Clubwagon XLT

 

> In your research, did you happen to find anything on the logic of the PCM
> that causes it to put the vehicle into safe mode.

Other then the power and loss ground, only heat related failures of the KAM, which is really a general failure of a larger chip because the KAM is only a 512 byte address space within 1-2 chips totaling 64k. The ram chip should be marked 81c61.

Basically, what happens is the CPU and components are only rated for 180 int. use. When the weakest link fails from heat (eprom or ram) you get a KAM failure which is really a disguised component failure of ram.

I would be happy to e-mail the above pdf to you.

Steve, I agree. I always thought redoing bad work done elsewhere was good business.

Someone else mentioned it and I thought I would agree, look for the harness being pinched somewhere.