BAD MPG
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5th Wheeling
Joined: Dec 2017
Posts: 25
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BAD MPG
I took my 2017 F150 4x4 into to the dealership for its first oil change/service. I have been experiencing a towing issue with the “TRAILER DISCONNECT” message popping up about every two minutes on a 60-mile run. Gets just a bit annoying after the 60th time of going off. The dealership claims the problem is in the trailer not the truck. OK I will rewire the trailer and hardwire it all the way to the plug. I wanted a new trailer plug, but they would not install it because they didn’t think it needed it. DUH?
The other problem the came up after the service my mileage dropped from 18 MPG to 12 MPG. WHAT The $%^&? Anyone have any ideas why the mileage would drop? I am not driving around in 4-by mode nor am in in any gear besides drive.
The other problem the came up after the service my mileage dropped from 18 MPG to 12 MPG. WHAT The $%^&? Anyone have any ideas why the mileage would drop? I am not driving around in 4-by mode nor am in in any gear besides drive.
More Turbo
Joined: Jan 2009
Posts: 530
Likes: 2
From: LI, NY
Re. “TRAILER DISCONNECT”:
If the trailer wiring was shorting to ground you would be popping fuses, so look for an open. The trailer wires could be loose inside the plug, start with the ground wire, check both ends and the wire run. If the ground opens your Ford will 'think' the entire trailer has gone AWOL.
If the trailer wiring was shorting to ground you would be popping fuses, so look for an open. The trailer wires could be loose inside the plug, start with the ground wire, check both ends and the wire run. If the ground opens your Ford will 'think' the entire trailer has gone AWOL.
Fleet Mechanic
Joined: Nov 2016
Posts: 1,634
Likes: 72
How would the forum's help be different for either of his issues on a 2017 4x4 whether it was an X (Screw, long bed, 3.5EB, trailering at 40 mph, 10,000 miles) VS an XYZ (single cab, short bed, 3.3NA, trailering at 55 mph, 30,000 miles)??
Are certain size trailers or brands of trailers known for having frequently faulty wiring? I would think the age of the trailer may be useful to determine if where the OP lives may have caused corrosion issues (1 year old and in the desert VS 20 years old in Michigan).
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5th Wheeling
Joined: Dec 2017
Posts: 25
Likes: 0
Many times, all this additional info is helpful....but I don't know how it would help address the OP's concerns.
How would the forum's help be different for either of his issues on a 2017 4x4 whether it was an X (Screw, long bed, 3.5EB, trailering at 40 mph, 10,000 miles) VS an XYZ (single cab, short bed, 3.3NA, trailering at 55 mph, 30,000 miles)??
Are certain size trailers or brands of trailers known for having frequently faulty wiring? I would think the age of the trailer may be useful to determine if where the OP lives may have caused corrosion issues (1 year old and in the desert VS 20 years old in Michigan).
How would the forum's help be different for either of his issues on a 2017 4x4 whether it was an X (Screw, long bed, 3.5EB, trailering at 40 mph, 10,000 miles) VS an XYZ (single cab, short bed, 3.3NA, trailering at 55 mph, 30,000 miles)??
Are certain size trailers or brands of trailers known for having frequently faulty wiring? I would think the age of the trailer may be useful to determine if where the OP lives may have caused corrosion issues (1 year old and in the desert VS 20 years old in Michigan).
I am more concerned with the mileage drop from 18 mpg on the highway withOUT the trailer to 12 MPG.
Fleet Mechanic
Joined: Nov 2016
Posts: 1,634
Likes: 72
Once you get the new one, pack the heck out of it with dielectric grease (including the factory side, not just the trailer connection side).
Laughing Gas
Joined: Mar 2004
Posts: 1,019
Likes: 6
From: Fountain Valley
What are you towing. My 2013 Eco max-tow went from 17 to 12 when towing a 20' enclosed car trailer and my new 18 5.0 went to 12 also on the same towing trip.. My 04 250 diesel was the same. I climb the same 4000 pass from sea level. The 13 seemed to have more power but the 18's trans gear selection was a lot better.
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Fleet Mechanic
Joined: Nov 2016
Posts: 1,634
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What are you towing. My 2013 Eco max-tow went from 17 to 12 when towing a 20' enclosed car trailer and my new 18 5.0 went to 12 also on the same towing trip.. My 04 250 diesel was the same. I climb the same 4000 pass from sea level. The 13 seemed to have more power but the 18's trans gear selection was a lot better.
I cant think of anything they could do to cause it during a regular service.
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Lead Driver
Joined: May 2015
Posts: 5,871
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From: Mts. S. of San Francisco
If you put an OBD II (ELM or whatever) on it, you should be able to look at the fuel trim. I'm going to bet it's way off because of some other issue. I'm surprised it's not throwing codes.
Lead Driver
Joined: Sep 2003
Posts: 5,844
Likes: 5
From: Albuquerque
Here are steps that I would take...
1. Check your oil level (follow the recommendations from your Owner's Manual on proper method) -- It has been discussed that the dealer will not add the proper amount or actually overfill the level.
2. Check your air filter and assembly to make sure they installed it correctly -- It is my understanding that they will at least look/inspect the air filter during the service.
3. Check tires are properly inflated
4. Check paperwork from dealership -- Did they take an opportunity to "UPDATE" your PCM/ECU with a new flash? If yes, then your truck will take time to relearn the fuel management process.
One variable could be that you are now using Winterized fuel. Now, your mpg's shouldn't drop that much...IMHO, but ??
biz
1. Check your oil level (follow the recommendations from your Owner's Manual on proper method) -- It has been discussed that the dealer will not add the proper amount or actually overfill the level.
2. Check your air filter and assembly to make sure they installed it correctly -- It is my understanding that they will at least look/inspect the air filter during the service.
3. Check tires are properly inflated
4. Check paperwork from dealership -- Did they take an opportunity to "UPDATE" your PCM/ECU with a new flash? If yes, then your truck will take time to relearn the fuel management process.
One variable could be that you are now using Winterized fuel. Now, your mpg's shouldn't drop that much...IMHO, but ??
biz
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