Security system locked my car after replacing PCU

Tiny
JOYCE FEHRINGER
  • MEMBER
  • 2005 FORD FOCUS
  • 2.0L
  • 4 CYL
  • 2WD
  • AUTOMATIC
I put a new PCU with new cut keys in my car. For some reason it thought I was stealing it. It wont recognize the keys to set them and nothing works. Well the day runner lights come on but every thing else doesn't work. How do I reset my security system? Oh, I put the old PCU back in the car hoping it would recognize that brain and key, so I could take it some where to have the system reset, but its locked out too. Can someone help?
Sunday, July 28th, 2019 AT 7:45 AM

3 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Hi Joyce,

When you say PCU are you referring to the PCM? If so, you cannot just replace this part. It requires you to program the replacement module. I attached the process on how to do this. It requires the use of a scan tool so if you don't have one then you will need to have a shop program it for you.

However, you are correct in that the vehicle thinks it is being stolen so it locks out operation until until it is programmed properly.

Please let me know if I am missing something with what your issue is. Thanks
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Sunday, July 28th, 2019 AT 10:11 AM
Tiny
JOYCE FEHRINGER
  • MEMBER
  • 2 POSTS
Im sorry I meant the PCM (brain). I had it programmed and 2 keys, to my cars VIN # and part # of the PCM, was there another part I needed to have programmed too? When I had the keys cut for my ignition one key wasnt cut deep enough so I took it back to have it re cut, it fits now. I was told that is my problem. I cant believe that to be so.
Was this
answer
helpful?
Yes
No
Monday, July 29th, 2019 AT 6:38 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Okay. That is good, but we just need to be sure they loaded the programmable memory into it. They do this when it is on the vehicle. Take a look at that first attachment and read under the Manual data section. Part of this information that is loaded into it is not only the VIN but the key information.

I suspect the best option at this point is to have a scan tool hooked to it and see if they are able to communicate with the new PCM. If they can, then they should be able to determine if it was properly programmed. If not, they can do it.
Was this
answer
helpful?
Yes
No
+1
Monday, July 29th, 2019 AT 7:21 PM

Please login or register to post a reply.

Related Disarm Content

Security System Reset
GUIDE
Security System Reset
Need to re­set the se­cu­rity light in your car? If the se­cu­rity light is blink­ing the im­mo­bi­lizer sys­tem is en­abled and will not al­low the car to start.