So here's my situation and hopefully someone smarter than me can help out. As most with a 11 or 12, 3.5 Ecoboost owners, My electric vacuum pump was replaced under recall. This was done about 40K miles & 2 1/2 years ago. The truck started having the problem again about 1year ago but I have been driving my 2016 I picked up used. Seeing as i am over 150K miles I knew Ford wasn't going to do anything for me on this. My problem is not only is this 2nd EVP bad as it wont run on a bench with power to it, but I am not getting any power to the pump. The fuse is good & I have power to the relay in the distribution box. What activates the relay to send power to the EVP? Am I looking at a PCM issue here? Any help is appreciated. I am looking to turn this truck back into an everyday driver to keep miles off my 2016 F150.

 

BJB fuse F54 (HOT in Start or Run) supplies power to the high side of the relay's coil. The low side of the coil is grounded by an output of the ABS module to send power from BJB fuse F64 to the EVP.

The ABS module uses a vacuum sensor in the booster to control whether or not the EVP is run to maintain vacuum between an upper and lower limit.

 

Thanks for the reply SHO89. Do you know if this vacuum sensor is internal and non replaceable or does it use the same one as the 4WD system that mounts outside the booster? I had a small local shop look at it real quick and he said he thought the ABS module might be bad but couldn't be 100% certain. I don't want to start hanging parts without trying to get a thorough diagnosis. I've tried finding a wiring diagram online for the ABS but good luck with that.

 

It's the sensor mounted on the front of the booster. It's easily replaceable.

 

Thanks for your help on this SHO89. There was no power coming out of that vacuum switch going to the ABS module. I replaced it for 25.00 and I have power to the EVP now. I still need to replace the EVP as it isn't working but I ordered a Dorman replacement today. Not going with OEM as that is the 2nd one in 2 years. I'm also planning on putting a catch can on the truck as I'm sure all the condensation in the vacuum system from CAC is what caused both of these to fail. Your help is very much appreciated.