P0340 Error Code after SCT 2 days from the SCT install?

[bigray327]

Daniel, here's what you should do: 1. Relax. 2. Breathe. 3. Change your dang alternator.

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[Daniel60]

thanks, I'll do that. i called the dealership and he agreed to check the alternator and coil packs tomorrow. He wants the car all day that's cool I want peace of mind.

[bigray327]

Originally Posted by Daniel60

thanks, I'll do that. i called the dealership and he agreed to check the alternator and coil packs tomorrow. He wants the car all day that's cool I want peace of mind.

Good. FYI, your car doesn't have coil packs like previous Mustangs, it has coil-on-plugs. Thus no spark plug wires.

[gburke1]

Same code happened to me, was caused by radio interference by a bad alternator.

[Daniel60]

bigray327 your the man!!! Today after dropping off the car at the dealership and going back home I received this phone call saying the same repetitive stuff they told me the other day, "Your ECM is losing it's memory because you have changed your computer chip. I told them , Hey that's possible but just take one more look at the alternator and camshaft senor and they agreed. One hour later I received this phone call saying hey it's your alternator. I'm like $hit Mustang Forums came through again. You see I have 77,000 miles on my car with an extended warranty and I do have mods but the dealership has been very professional about it and stuck to the guidelines that whatever you replace will be voided on the warranty. I told them that mustang forums had this documented on the forums and they took heed to check it out. At first I was a sitting duck because their computer said it was my computer and they wouldn't be able to fix it. Now I did pay a 100 dollars deductible but I also saved 381 dollars and 51 cents.

Parts 329.27
Labor Mechanical 127.54
sub-total 456.81
Tax 24.70
Total 481.51

Thanks Western National and Mustang Forums for keeping the mustang world and ford dealerships educated. This isn't the first time this forum has came through for me. I need to make another contribution again.


this is what was printed on my receipt.

CONCERN 51
CORRECTION TESTED SYSTEM -I-0340. PERFORMED PINPOINT TESTS AND FOUND D10DE PATTERN IN ALTERNATOR BAD. RF INTERFERENCE CAUSING CAM SNSOR TO REAR IMPROPERLY.

51-1 REPLACED ALTERNATOR AND RECHECKED-OK


So far no check engine light and I did do an extended ride to ensure with great grief but to my satisfaction no check engine light. Fu$king outstanding.