Car will not crank. PCM issues?

[oh5gt]

Ok, up till now I have not really needed to post questions, they are all here somewhere. This got me stumped.

2005 mustang GT. After being parked for 6 months it will not crank. battery is now good but was dry. I had the starter off the car and it works fine on the bench. The relay does not click. All other functions seem fine. I have performed all the checks and tests in the shop manual.

It all leads to a defective PCM.

PCM replacement requires some sort of configuration and a sync with the keys. Seems the dealer needs to do this. I tried to book the car in to have them check it, 6 week wait for service. I have no problems replacing the PCM myself, but i think the dealer needs to configure it. Is this correct.


One or two other twists. The car has a remote starter and sometimes when I change the tune I have to push a microswitch under the dash to reset the system. When I first tried to start the car after storage i tried this switch and it cranked once very slowly. Could the problem be with this remote starter system?

Also. I had a charger with quick start feature connected when trying to start car. Did this fry the PCM? Did I immobilize the secuity system somehow?

Car is not throwing any error codes.

Can anyone share some advice on this one?

 

[TexasBlownV8]

Still sounds like battery. If it was dry, it's toast. If is still the stock '05 battery, it's gone for sure.

 

[shanec]

+1 for the battery. At least try some jumper cables.

 

[RRRoamer]

Factory remote start or aftermarket? You need to get the schematics and start digging. If you know how to read schematics and have a few basic tools, you should be able to see if the PCM is getting the start signal when the key is turned. If it isn't, I would lay money it is the remote start unit that is hosing things up.

As for PCM replacement, yes, the dealer has to initialize the new PCM. I went through this about two years ago when I was having some stalling issues. Everything pointed to the PCM and it was replaced under warranty, but it turned out NOT to be the PCM. No codes either. I would ASSUME (and ONLY an assumption!) that if you get a replacement PCM used for the same model and optioned car, it would be a bolt in.

Good luck getting this resolved.

PS: I assume you have replaced the battery? If it was flat after sitting for 6 months, it IS dead, I don't care what voltage it is sitting at coming off a charger.

 

[Kuro!]

If you are sure your battery is fine, try jumping the starter solenoids.

 

[oh5gt]

Thanks everyone. quick replies.
Well i replaced the battery. No luck. Tried the solenoid, solenoid engages, starter does not.

Seems I am getting a display now (maybe before, never noticed) on the dash 'security event occured' I'm going to book a appointment at another dealer the PATS system is beyond my abilities.

 

[shanec]

Try leaving the battery disconnected overnight and/or apply the brakes with the battery disconnected. Just a shot in the dark - but maybe resetting the PCM like that will help.

 

[psycho bob]

you said the relay wasn't enguaging. did you try a known good relay in it's place. you can change out a different one from something like the horn you can figure out is for sure good.