Question

2005 Ford F250 5.4L with engine code P1633, what can I do to fix it?

Answer 1

You have an 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.

P1633 FORD Code - Keep Alive Power Voltage Too Low
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