P401 code
Thread Starter
Senior Member
Joined: Oct 2011
Posts: 426
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From: South Carolina
P401 code
Hey guys today my truck threw a p 401 code and want to know what's causing it. Also a week ago I noticed my AC only blows out the defrost vents and no matter what setting you put the selection **** on hot or cold it still blows out the defrost vent. I was wanting to know if the vacuum leak that's causing it to only blow out the defrost vent could cause that code. Truck is a 99 f150 4x4 with the 5.4. Thanks in advance, Clay
Senior Member
Joined: Jul 2010
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From: Alaska
98 F150 5.4L E40D/4R100
Joined: Nov 2006
Posts: 28,519
Likes: 7,631
From: MI
The 401 has nothing to do with your AC and defrost, - not sure why you would combine the two. I 'll contribute to your thread title heading and first problem, -
That's almost always a DPFE problem.
That's almost always a DPFE problem.