04 explorer xlt wont start after replacing battery

[coolwwebb]

Ok here we go, I have a 2004 Ford Explorer XLT, I replaced the battery cause the old one start to die on me many time, after replacing the battery the truck wont start, I have a error code B1601, PATS received incorrect key-code from ignition key transponder. I have try both key both wont work, I check the ECU and it say I have 3 programmed key. The red light on the dash flash very fast when turning the key on.
I have checked all fuse, relay, and still wont work. checked starter and turn no problem when bypassing the starter relay.
any one can help what will be next to try it out, cause will prefers fix the truck my self then the dealer. ANY HELP WILL BE VERY APPRECIATED.
Thank you in advance.
David

 

[DAT05EXPLODER]

is it trying to crank or just nothing at all?

 

[coolwwebb]

no crank

is it trying to crank or just nothing at all?

No crank turn the key nothing all light work on the dash, starter turn
And engine cranck if using a bypass on the starter relay replaced relay still same problem.

 

[thepotroast]

Look at:

http://www.explorerforum.com/forums/showthread.php?t=230995&highlight=b1601

Did you replace it with the correct relay? Seems that this solved a lot of issues for other members who had the same experience. Otherwise it sounds like it could be a bad PCM

 

[coolwwebb]

no start

I have a scanner to reprogram lost key or new key, I look into the ECU and got 3 key programmed. So I try to reprogram the key and it say key not found after 4 min of programming??
Should I remove all programmed key on the ECU and try with the same old key and reprogram them?
I still have that error code B1601 event after trying to remove the code.
The red light on the dash blink very fast when key turn on run position
If bad PCM I do test to see if it is broken?
Thank you for all your help hope someone can help me to find the problem.

 

[DAT05EXPLODER]

Have you tried to program a new never programmed before key? If you have the machine to program a locksmith could cut the key for you.