I have a 2005 Ford Focus 2.0L check engine light is on has code P1633

Question

Ok, I have a 2005 Ford Focus 2.0L check engine light is on has code P1633. I had it cleared but the light came right back on.

Answer 1

P1633 Keep alive power voltage too low

You have open circuit with the KAPWR (keep alive power) to the ECM, and this will cause the CK ENG LT to illuminate immediately.Check the fuse listed as KAPWR  it will be in the fuse box on the passenger side this is the CJB (center junction box) if you have the owner manual it should show  the location. Ford is very vague in giving the location.

Answer 2

P1633 FORD Code - Keep Alive Power Voltage Too Low
Read more: https://www.autocodes.com/p1633_ford.html