Replace ECM

[Tone]

2004 expedition I think lost 5 volt reference. I want to know if I'm able to use a junkyard ECM using my autel scanner.

 

[Tone]

If someone can help pin point this 5 volt ref issue I'm having that would be great

 

[whtbronco]

There's a chance you can use a salvage yard PCM/ECM, but you'll need to ensure your scanner can write to the modules to clear memory, update the list of options on your truck etc.

I think to figure this out you're gonna need access to wiring diagrams and pin point tests. I use AllDataDIY, Mitchell has an online subscription as well.

Another option is to download the service manual. I'm always concerned about malicious software possibly included in these free downloads though. https://charm.li/Ford Truck/

 

[Hamfisted]

I would not recommend a junkyard PCM. Have you tried swapping the PCM relay with one of the others at the top of the fusebox, just to test the relay. The PCM relay is the top right relay. What is the Expy doing, or not doing ?
A new programmed PCM is around $200 from Flagship One. 2004 Ford Expedition PCM at FlagshipOne

2004 Expy Wiring Diagrams







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