Sorry, I don't remember - it has been a couple years for me too. Try plugging in and looking at that options under the programming or config button. I may be confusing it with a PATS module sync, but I'm not sure.

They ask for the VIN when you order the ECM so it's surprising that they would give you the wrong one.

 

Thats fair. And yes, I gave them the VIN and they said that there should not be any programming needed on my side. I got an email reply from my account manager today and she said she will be setting a return for them to diagnose it. If i have time, I will try to run through it with Forscan before sending it back or do you think its not worth it (because I am not sure exactly what I am looking for in this instance)

 

I would probably try it one more time if you have a spare 30-40 minutes. And you might want to hit the forscan forums for tips or pointers.

 

I didnt get the chance to run through forscan as it was on my old PC and I am on a Mac now. Anyway, the ECM is enroute back to Flagship One. I will post back after they run it through diagnostics.

 

Hey, late to the party here.
I'd like to point out that I've seen dozens of times where a tech doesn't begin diagnostics in earnest until after the PCM is replaced. Since the customer shelled out a wad of cash for a PCM that didn't fix it, the wiring problem that eventually fixed the issue is never reported. Long story short, be skeptical about reports that a PCM fixed a circuit hard-fault.

My explanation of this DTC: The EPC is "ground side switched" meaning when the key is on it is "hot". PCM applies ground to make it work. When no ground is applied, the voltage travels through the EPC back up the switching ground wire to teh PCM. PCM merely verifies that voltage is present when deciding if the EPC is okay. If no voltage is present, it sets and open circuit DTC. If ground is present, it sets a "short" DTC, which is what you've got. So that 1 wire is shorted to ground. You can eliminate the PCM as a possible cause by unplugging it and checking for the presence of ground on the EPC wire. If it's still grounded with the PCM disconnected, it's not the PCM. Unplugging the trans in addition to the PCM and still finding ground on that wire will also eliminate the EPC or internal trans harness as a possible cause.

The most common place for the harness to cause trans faults is where the external trans and o2 harness passes by cylinder #4, the rear, passenger side cylinder. The harness falls off the valve cover stud that holds it up and it touches or gets too close to the exhaust manifold, gets hot and starts causing probs. The harness(es) also short against the a/c accumulator/drier and the sheet metal bracket that sits below the starter relay. HTH.

PS: I'm not sure about the EPC but some outputs, like the IAC valve do not like high duty cycle. Having the control side/ground side wire shorted to ground means the output is stuck at 100% duty cycle whenever the key is on or in start. So it might have damaged your EPC, IDK.

 

Same as I replied in my post 6 in condensed form.
But no, it had to be something else by the next string of replies.

 

Dude wants to put a PCM in it. Diagnostic pinpoint tests/flow charts for circuit DTC's are set up for hard faults- faults that are present while testing- most circuit DTC's are intermittent. Try doing a pinpoint test for an intermittent fault that is not present while testing and, more often than not, you get to the part where the pinpoint test says "replace PCM".

I think mechanics would be better served by not having flow charts or pinpoint tests for something as simple as a circuit fault. It would force them to think instead of skip to what parts to replace.

 

UPDATE: It was a bad PCM. I bought a used one (second one as the first one had PATS enabled), and she fired right up and no codes. I have put 200 miles on it and no codes and transmission shifts perfectly. Hope this thread is helpful to someone in the future.

 

Removed

 

2 Year Update: For sure was a bad PCM. Two years and no issues. Hope this is helpful to others.