Page updated on 05-21-2018

truck dies while driving

01-21-2011, 02:19 PM
I have an F-150 with a 5.4L EFI and A/T. For the past two days while driving along the engine just cuts out. There is no chugging or sputtering. It just dies. When it happens, I place the trans in Neutral while still rolling along and it starts right up.

I had suspected it might have been a bad eec relay and connector that I had trouble with in the past, but I changed that all yesterday and the problem happened again today.

Any help would be greatly appreciated.


01-21-2011, 03:36 PM
1)How old is the battery?
2)Is there any corrosion around the battery terminals, or cable?
3)Can you turn the battery terminals by hand?

Have your battery, and alternator load tested to rule them out!

01-21-2011, 07:11 PM
You forgot to mention the year. A loose connection on the crank sensor can cause your problem.

01-22-2011, 01:53 PM
I'm sorry people - the truck is a 2001.
I just changed the crank sensor ($25 part from Carquest) and it was a fairly easy job. Only obstacle was the A/C compressor which I had to unbolt and move to the side to make room to remove the sensor. The compressor is held in with three long 10mm bolts, two closer to the engine and one on the outer side of the compressor(that was the hard one). You can access the bolts from the underside except for the third one which is more accessible through the wheel well over the tire. Oh Yeah, first you have to remove the drive belt, don't take it off just release it so you can move the compressor. The sensor is held in by one 8mm bolt and it came out easy. removing the sensor was a bit of a juggling act as I had to keep shifting the loose compressor to make enough room to slide the sensor out. The new sensor went right in and the compressor was an easy bolt back in.
I did notice that there was moisture inside the sensor receptacle and the connector also had moisture. I sprayed the connector with an electrical contact cleaner and then blew it out with air to dry it.
Took the truck for a road test and it ran fine. I only drove it for about two miles though and I won't know if the problem has been solved until I take a longer drive, which I should be doing tomorrow.
If the problem still exists, my next step is to change the sensor connector which I found online at NAPA for about $12.
Thanks again for any input you guys gave and if the problem still exists I will post again, otherwise the problem is solved.

02-02-2011, 05:45 PM
Since I changed the sensor the truck had been fine, until today. I was exiting an interstate and while slowing down on the exit ramp for a yield sign I felt the tranny downshift and the engine went dead. I pulled to the shoulder, placed the tranny in Neutral and the engine started right up. I then drove 5 miles to my destination and a few hours later 25 miles to my home with no problems.
Any help or ideas would be greatly appreciated.


02-02-2011, 06:11 PM
Doe's the weather play a factor, rain, snow, Ice, or a car wash?
1) Roll the fuel pump Relay to another location to rule that out too!

02-02-2011, 06:24 PM
I thought it might have been a weather related problem because when it first happened we were having some single digit and below zero temps. But today it was in the mid 30's when it happened.
I don't think the problem is fuel related because usually fuel problems cause fuel starvation and as the fuel supply is cut off the engine usually sputters or chugs along until it stops. The problem I am having is that the engine just dies as if someone turned a switch off.
I am hoping that it is a wiring, sensor, or relay issue and not the PCM. The PCM is not cheap.
Nonetheless, thanks for the reply.

02-02-2011, 06:30 PM
Compare the #'s on the relays, you might beable to roll the PCM relay to another pos too!

I have no problem getting fuses, relays, bulbs, and used sensors at the salvage yards.

big white bufflo
02-02-2011, 07:21 PM
i think i seen a post on here about a lose or corroded connection on the pcm have you looked at that

02-18-2011, 07:29 AM
The truck's not throwing any codes and it happens when cold as well as when hot. I don't think it's gas related as usually when the fuel delivery is interrupted or cut off, engines usually sputter before dying; mine just shuts right down.
I spoke with a service writer at a Ford Dealership and he could not offer any definitive solutions. He said that it could be anything from a loose wire, bad ground, or water intrusion into one of the electrical circuits.
Nonetheless, the other day I drove to a store and after five minutes in the store, the truck would not start at all. I have had problems in the past with the EEC relay (located under the hood next to the power distribution box). There have been times when the truck wouldn't start and I would tap on the EEC relay and push the wires into the connector and the truck would start right up. I previously changed the relay and I reinforced the wire connections. Well, I still had the old relay in my glove box so I tried it and the truck started right up. I bought a new relay but had not yet installed and then the same thing happened so I installed the new relay and it started.
Then while driving home, three times the engine cut off on me but each time started right up.
When I got home it died once in my driveway and then started. While it was running I began to poke around under the hood, tapping and jiggling various connections and when I tapped on the power distribution box the engine died and would not start again.
I removed the power box and checked all of the connections between the EEC relay and the box and all were okay. I also checked all fuses inside and under the hood and all were okay. I did notice some grease or lubrication on the terminal connectors of the EEC relay harness plug. I sprayed them with an electronic cleaner and reinstalled the relay and the truck started right up.
Now I'm thinking the problem may have been poor contacts at the EEC relay connection.

Although the fix was not definitive, the problem has apparently been resolved. My belief is that the EEC relay blades were making poor contact in the relay harness plug. As I had said, there was a greasy type lubricant in the harness plug where the blades insert. Apparently by cleaning them with an electrical terminal cleaner spray, the EEC relay is now making good contact. I did notice that prior to cleaning the terminals, the relay could very easily be pulled in and out of the harness plug. Now, that the terminals are dry, the relay appears to be much much snugger in the harness plug.
I have already clocked over a couple of hundred miles with numerous starts and stops and the engine has always started immediately and it has no longer died while driving.

06-27-2011, 12:06 PM
FYI for all - The initial problem reared its ugly head again. I was driving on the interstate and the engine just cut out on me. I pulled over to shoulder and I removed the power distribution box from its perch and on the underside of the box I manually pushed each wire connection into their respective terminal to insure good connections. Then with the box resting on its side I tried to start the engine and it started right up. However when I turned the PDB to reinstall it on its perch, the engine died. This happened a few times and it became apparent that the problem had to be a faulty wiring connection or even a break in a wire.
I was able to jimmy-rig the PDB with tape and a coat hanger so it would remain on its side so I was able to get home.
Once at home I began to check and test each wire uner the PDB using a test light and also a continuity light. During the process I observed that whenever the engine was running and I touched one particular wire, the engine would die. The wire was a lead to the fuse that controls the PCM and fuel pump relays. It turns out that the socket where the fuse plugs into was spread way too wide to hold the legs of the fuse firmly. I dis-assembled the fuse socket and then crimped the terminals tighter and replaced the fuse and the problem seems to have been completely solved.

09-12-2011, 09:23 PM
check your altenator and or voltage regulator could be causing it to cut off a bat alternator can shut your engine down

Vicki Tuning
01-21-2014, 04:14 PM
My truck is doing the exact same thing started 2 days ago. I have 2002 F-150

Add your comment to this topic!