The check engine light came on and it ran rough for about one mile went. Did key on Engine off test and got 334 10 512. Any help would be appreciated.
94 F250 5.8

 

334 = EGR closed valve voltage high
10 is a separator
512 = KAM test failure (Keep Alive Memory) which usually indicates your PCM is bad and needs to be repaired/replaced. That is the one I would concentrate on first.

 

If the PCM is bad would it do it all the time or intermediate times?

 

It can give wonky codes and make the CEL come on yes from what I have read.

Most posts I have read about it, it is caused by 3 capacitors leakig due to age and corroding the connections. Some replace the capacitors themselves. I bought a reman PCM as I needed the truck on the road ASAP. I am pretty good with electronics and soldering but it was a time is money situation.

 

Thank for the help.

 

Code 512 can be triggered by removing the battery cable then re-installing it. Some do this to clear the stored codes from Continuous Memory. The proper way to clear CM codes is to start the KOEO tests, then remove the ground on the STI connector as the codes are flashing out.

 

I will try thanks

 

Just had an issue running rough at idle. Got a 334 code. EGR was bad, sticking open. 93 F350,7.5

 

Update, we cleaned the PCM connections and used dielectric grease and replaced the PCV valve and all seems good now.

 

good deal. hope it runs well for you for a long time..

 

Turned out the problem was the distributor and plug wires