1988 F250 4x4 300 I6 ZF5 manual with 3.55 rear axle.

Hi everyone, and a big thank you to all of you for the information I have learned from the forums.
I was on the point of selling my truck a couple of years ago when I stumbled on this site. The enthusiasm you
all have for these trucks infected me and I am now proud to be one of the group.
My question today is about the EEC/PCM.
The original information sticker on the door jamb of my truck has been deliberately defaced and a new sticker applied (8-51E-R00).
So I have to assume that the computer was changed at some point. This has me wondering what the original calibration would have been and why is it different now?.
Also I scavenged a computer from a 95 F150 5 litre with a 5 speed manual transmission and and am wondering if it would work in my truck, and if not, can they be recalibrated?

 

The 1995 computer won't work. You need a 4.9L computer, and it needs to be pre-1991. Someone can correct me, but around 1991 / 1992 the engine control was changed. The 1995 computer won't work with the 1988 wiring harness...

You can't really recalibrate the computers either.

Why are you wanting to change out your computer?

 

I am looking around for a spare in case of future trouble.Want to make sure I get the correct one.

 

Somewhere I have an ECM from a 90 with exactly the same drivetrain. PM me if you are interested.

On getting exactly the right ECM, yours will be EECIV. Wiring on all the EECIV computers is very close.The change that is mentioned above likely is the EECV change that happened in 96. Difference is the 60 pin/3 row layout vs. the 104 pin/4 row layout of the main connector. Physically, they are nearly identical. What does differ is the programming and yes, it cannot be easily modified. There is what is called a catch code on a sticker on the ECM. Calibration info from the door sticker is valuable, but that catch code is the easy way to identify the ECU. The catch code will vary from year to year, but if the drivetrain is similar, the ECM will likely work. 4/6/8 cylinder do not interchange and some of the later ECM's also controlled the automatic transmission. Codes will be set if the correct transmission is not connected.

 

I've never seen a ZF behind the 4.9, they have all been the Mazda trans, not that it matters, ecm will be the same. If you want a spare, pull your ecm and get the numbers off of it then go to Car-Part.com--Used Auto Parts Market
You can usually get one for about $50

 

I pulled the computer as suggested. There is a large three digit code 8TE, and a much smaller four digit 18. Which is the relevant one?
Interestingly there is a Ford sticker attached that says " Warranty Item, Do Not Open "
So perhaps the original was changed under a warranty.

 

Not sure what happened with my post there.
The four digit code should read 18

 

I will try again
the four digit code should read eight, D for delta, one , eight

 

The warranty sticker turned out to be a cover over a hole in the case for an unused connector.
The caps look fine so perhaps I should not be so concerned about getting a spare.
Still would like to know what the original catch code was.

 

For that sticker 8-51E-R00 it would be E8TZ 12A650-ZA or E8TZ 12A650-ZB see chart below.


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