Hi everyone,

A friend has diagnosed the ECU in my 1989 F150 as being the reason it won’t start. Local parts store and Rock Auto have a variety of remans, but the numbers are not identical. The manager at the local store says he’s not sure the replacement he’s offering is correct, and won’t guarantee it to work.

I’m hoping one of you can tell me for sure if this will work, or if I need to look on eBay or in junkyards. The original from the truck has E8TF-12A650-X2B.
The one offered is from Cardone, part 78-4469 and says it’s a replacement for E8TF XA and XB.

The friend who uninstalled it for me says they all have the 12A650, but he thinks the 2 is probably important, that X2A is not the same as XA. Does anyone know for sure?

Thanks!
ff6

 

Is the calibration sticker still on the driver’s door “B” pillar?


“Borrowed” picture.

 

This is why sending the original out for repair is preferred over the Cardone junk.

 

Yes, it is. Thank you for the helpful pic so it is obvious even to me!

In case you were going to ask, the numbers are
8-51F-R00
E8AE-6E061-ACR.

 

OK, I tried to do my own research, and found loads of places advertising they rebuild these. Any tips on choosing one that will do a good job? Thanks.

 

Ecmrepairs.com or if you want to swap just go carcomputerexchange.com as they have the largest inventory.

 

I do not have the books to look that up but there are people on here that do.

 

A truck with a calibration number of 8-51F-R00 needs computer (ECU) number E8TZ 12A650-XB.

 

Thank you!

 

I sent the unit out to ecmrepairs.com. They told me they replaced a capacitor, cleaned up some acid damage, and checked a trace. Didn’t sound like a lot, but what do I know?

Got it back a few days ago, but didn’t install it until today because of “side effects” from my 2nd Pfizer shot.

Turned the key to “On.” Fuel pump ran continuously without shutting off. Cranked the engine. It turned over but did not catch. Exactly what it was doing before.

For good measure, we tested the fuel pump relay to make sure that it was not stuck closed, and with the module out, we tested for a short in the wiring harness that would cause the pump to run.

Will call the good folks at ecmrepairs.com tomorrow and find out what their “lifetime warranty” is worth.

 

Even if you had bad wiring or relay that keep the pump running it would still start.
With that you know the clock is not running in the PCU (ECU).
Would be a bad PCU (ECU) or low voltage to the PCU (ECU).

To test the relay an wiring you would just unplug the PCM (ECU) and turn on the key.
If the pumps run now you know it is a bad relay or wiring.
If the pumps do not run you know it is a bad PCU (ECU).

 

That was how we checked for a short in the wiring. With the module out, the pump does not run. We also measured the default resistance across the relay. Which was probably redundant.

Sending it back to let them try again. My confidence level in the service is not high at this point, though.

 

Well did you get it straightened out, mine is the same numbers as yours, which is nowhere to be found, I will have to get mine repaired obviously.