Manager Forum

We have a 2004 F350 with a 6.8L V-10. Base model truck with no PATS.

It came in with MIL on for o2 heater code. Code set even though no problem was found. Determined PCM faulty. Replaced PCM and programmed. The fault went away and monitors ran. The next day the truck would not start and we had no communications. In a few minutes communication came back and truck started and ran without problem. The next morning we had no communication and no start. After ignition is on a few minutes communication is restored and vehicle starts and runs. Replaced PCM again and programmed. The same pattern continues. Our EASE programmer shows nothing to program except the PCM. If we reinstall the old PCM the starting problem goes away but MIL resets for o2 heater.

Any ideas?

First, are you confident in the quality of the replacement PCM's? Are they factory or aftermarket?

Second, the only other module on the bus for 2004 is the IC, which can cause a no start. During the failure, can you talk to the IC ? If no, then I would try unplugging the cluster from the network and see if that restores communication to the PCM. If yes then the PCM is suspect.

I've seen plenty of no-starts caused by the cluster taking the network down.

Thank you. We lose IC communications at the same time. I will leave cluster unplugged tonight and see what happens tomorrow. I am not confident in quality of PCM but Ford said they could not replace it because it is obsolete.

Well, that's good. This tells you that the network is going down. Now is it the cluster or the PCM?

Let us know what you find.

Third PCM did the trick. We purchased a PCM from a different supplier and that solved the problem. I love it when things go smooth.
Larry

There once was a time when we could rely on quality replacement parts. Today we are bombarded by "quality" parts that have been re-boxed over and over again due to buy outs or manufacturer retagging. I've become so accustomed seeing cores and damaged parts inside brand name boxes. I've seen boxes where the label area looks like an old suitcase covered with travel stamps. It almost seems I'll be able to tell my grand children once upon a time stories about part quality and availability. It seems the only part supplier I rely on is World Pac. Only exception is getting cooling and A/C parts from them. They look great but are off just enough where they will not fit. Gotten stung twice so now I deal with OEM only. Speaking of OEM they are getting a bit more competitive and if the wholesale cost was a bit more appealing I would use them a lot more. World Pac carries a lot of OEM parts but they are from the manufacturer that sells to the dealers such as Delphi and now I'm seeing Ford, GM, and a lot of Asian coverages. Many times my cost is 20% lower than what it costs the local dealers from the auto manufacturer.