Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

7.5l trouble code 542

Thread Tools
 
Search this Thread
 
Old Mar 18, 2018 | 08:11 PM
  #1  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
7.5l trouble code 542

Hey there,

I got this '94 7.5l with a KOEO 542 code.

Truck cranks but won't start. Fuel pump doest activate when key is turned on. I checked relay, inertia switch and tank selector and they all seem to have power.

Where do I go from here?
 
Reply
Old Mar 18, 2018 | 09:30 PM
  #2  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Short pin #2 to pin #6 and see if the selected pump runs with the key is in the run position.

Attachment 280124

Attachment 277922
/
 
Reply
Old Mar 18, 2018 | 09:38 PM
  #3  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
But the 542 code most of the time turns out to be a bad fuel pump.
 
Reply
Old Mar 21, 2018 | 06:38 PM
  #4  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
Jumped 2-6 with key on. No power to pump. Probably bad pump
 
Reply
Old Mar 21, 2018 | 06:48 PM
  #5  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
Another thing. If I turn the key off and on a bunch sometimes it kicks power to pump and runs fine then I turn it off and nothing.
 
Reply
Old Mar 21, 2018 | 08:37 PM
  #6  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
That would be like starting the fuel pump by hitting the bottom of the fuel tank with a rubber hammer.
Starts it sometimes.
 
Reply
Old Mar 23, 2018 | 05:51 PM
  #7  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
My truck has two tanks. Will a after the axle fuel pump work for both tanks?
 
Reply
Old Mar 28, 2018 | 11:34 PM
  #8  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
New fuel pump. Still get a 542 code
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Mar 29, 2018 | 06:25 AM
  #9  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Dose the PCM Power relay click each time the key is turned on?

Then if it does click while doing post #2 above does the fuel pump relay click each time pin #2 is shored to pin #6 with the key on?
If no does the fuel pump relay click each time pin #6 is ground to the engine with the key on?
 
Reply
Old Mar 29, 2018 | 05:44 PM
  #10  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
Relay clicks when pin #6 is ground to engine and when jumped to pin #2
 
Reply
Old Mar 29, 2018 | 06:20 PM
  #11  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Swap the horn relay with the fuel pump relay and see what happens.
 
Reply
Old Mar 29, 2018 | 06:28 PM
  #12  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
Nothing...

p.s. I connected a test light from engine to negative terminal of batter after removing cable connection and with key off and out the test light is lit.
 
Reply
Old Mar 29, 2018 | 06:30 PM
  #13  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
Sorry door was open when light was on. Now with doors shut key on. No negative cable to battery light is on
 
Reply
Old Mar 29, 2018 | 06:33 PM
  #14  
subford's Avatar
subford
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
More than likely that is normal.
You have the computer keep alive memory and the radio memory for two items for that path when doing that.
 
Reply
Old Mar 29, 2018 | 06:42 PM
  #15  
RanB's Avatar
RanB
Thread Starter
|
New User
Joined: Mar 2018
Posts: 13
Likes: 0
Oh ok. Hmm...
 
Reply



All times are GMT -5. The time now is 08:58 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE