KEVIN1969

I'm helping my neighbors daughter with her 2011 Mustang, she told me that the remote on her only key quit working and she went to the Ford Dealer parts dept. they replaced the battery and got it working, two days later her Mustang would not start, she thought it the car battery so she got a new battery at autozone, it still would not start so she had it towed home and asked me to look at it, I plugged in my Launch scanner code reader to the OBD2 connector and got a code P1260 and P1602 in constant memory, I cleared the code and tried doing a programed key reset, I had no luck, the P1260 returned after a 5-6 times of clearing code and trying key reset, P1260 kept returning ,but P1260 never did return, next I checked the driver info center reset and read My Key not programed, next it said two administration keys programmed . I think that the Pats immobilizer lost the key programming and now does not recognize the transponder key anymore, I've came to the point that I need some expert advise on what to do next, I think that she needs to buy two new keys and have a lock smith that has the capability to reprogram the keys, or have the dealer do it. Any good advice on this is much appreciated guys

08'MustangDude

The battery in the remote has nothing to do with the transponder in the key.
It is powered inductively at the ignition switch. Only the dealer can program
transponders into PATS. Anyone can program REMOTES...

P1602 would be the low voltage from the car's battery to the ECM.
P1260, theft detected, engine immobilized.

You have verified that it said two keys were present in memory, so it's either the
coil at the lock cylinder that powers the transponder, or the transceiver can't read it.
This sees this as an attempt to start the car without a PATs key, and sets the condition.

Also, if the car battery voltage was low enough, same thing, the coil would not power the
transponder in the key. SO, once the car battery is replaced, you need to put the key
in, turn the ignition to run, and wait a few minutes, or for the anti-theft light to stop blinking.
If and when it stops blinking, the car should be ready to start, the IMMO is reset.

If not, then it's a dealer trip to fix the transceiver or lock cylinder induction coil.

KEVIN1969

ok, that's what I thought, I already tried putting the key in and even though the light stops blinking after about 5 minutes as soon as I try to start it , it begins flashing again and has a continuous code P1260, I guess it's a trip to the dealership. Thanks for the information Mustangdude.

08'MustangDude

If you had a tuner, they can make a PATs disabled tune.

Check fuse #36 in the SBJ, it's a 5AMP fuse for PATs.
Fuse #11 is Security Module.

http://diagrams.hissind.com/2011-for...od-under-dash/

KEVIN1969

I just checked both fuses with my power probe2 and they're both good, I have 12V on both sides.

KEVIN1969

I don't have a tuner.

08'MustangDude

If there is a serious problem, a tuner may be cheaper in the end, plus, you
get the benefit of some more power. I have a remote starter, but have three
keys, so I am debating tuning out the IMMO, or using a key for the module...

KEVIN1969

Thanks for the information, I'll ask around and see if anyone around here has a tuner, I think it's better to delete the immobilizer, won't have to deal with it again, and you can cut a key and it will work if you ever lose them.

08'MustangDude

I believe SCT has PATs disabled tunes. Ask some questions before buying...

https://www.facebook.com/marketplace...3106902404825/
$100.00 unlocked.

KEVIN1969

ok, thank you