Fuel gauge WILDLY inaccurate

[md13ffhguy]

My fuel gauge has gone completely out of whack. I filled up 6 days ago, and over the course of three days (at least 200 miles), the fuel gauge remained pinned at the highest reading - just above F. I knew this was incorrect, as I've previously had an issue (off and on) where the reading would actually INCREASE as I drove. http://fordfusionhybridforum.com/topic/9906-incorrect-fuel-gauge-reading/As described in that thread, the dealer did flash some software, but the problem persisted intermittently (the worst kind of problem...). At times, it will stay "normal", but will freak out on occasion, and after a few days will return to normal.

 

Anyhow, last Friday, I parked it at home with the gauge still above F. Monday, I started it up after not driving it over the weekend, and it showed about three quarters full. I think it should have been around half by this time, but no matter - as I drove to work, it began decreasing as I watched! After about 20 miles, it was on E - the low fuel warning popped up and the icon turned yellow, and a few minutes later - red! The miles to empty had dropped all the way to 0, and then just ---. And then later in the day, it's showing a nearly full tank. The fluctuations are very disconcerting (especially when the car warns me I'm running out of gas), but I've learned to deal with it.

 

I haven't seen anyone else report such an issue, and I have no interest in visiting a dealer just to have a mechanic "guess" at what might be wrong. Maybe someone here has an idea, or maybe even a knowledgeable Ford technician might read this and chime in... At this point, I'm used to just tracking the miles driven and gallons used for each tank, and refueling when I'm around 500-600 miles or about 11 gallons used, give or take.

 

[Waldo]

Well the fuel level input is one of the very few signals that is still sent over a hardwire - not over the network. So it can only be one of two things:

 

1. The signal coming from the fuel level pump assembly is faulty

2. The cluster is not processing the signal correctly.

 

Either way, should be pretty straightforward for a tech to figure out which of the two it is.

[Texasota]

Well the fuel level input is one of the very few signals that is still sent over a hardwire - not over the network. So it can only be one of two things:

 

1. The signal coming from the fuel level pump assembly is faulty

2. The cluster is not processing the signal correctly.

 

Either way, should be pretty straightforward for a tech to figure out which of the two it is.

If it is an intermittent short in in the "hardwire" it may be difficult to reproduce and diagnose. Md13ffhguy, does the random behavior occur while the car is stationary (i.e. no vibration or movement) or does it occur only while driving?

[md13ffhguy]

If it is an intermittent short in in the "hardwire" it may be difficult to reproduce and diagnose. Md13ffhguy, does the random behavior occur while the car is stationary (i.e. no vibration or movement) or does it occur only while driving?

Well, I only notice the changes while moving, however, lately it's like roulette when starting the car. I never know where it's going to start out, or if it's going to go up or down! I can't say I've watched it for long while not moving.

[Texasota]

Might be interesting to start it in your garage (ICE not running) and let it sit there for a while and see what happens. If it jumps around that might be another clue for your service department.

[hybridbear]

Crazy! I'm really surprised that Ford couldn't fix this before. Replacing the fuel level sender seems like it would have been the first step. Did you first report this concern before the 3/36 warranty expired?

[md13ffhguy]

So, I've learned what's probably causing this problem. When I had it in for recalls, they checked the wiring coming from the fuel tank area and discovered a connector near the bulkhead in the area of the left wheel well. I was told when they pulled the connector off, water came out of it and the connections were corroded. I was given an estimate of $600+ to repair, but they did not do the work, as the part was not in stock anyhow.

 

I asked if perhaps this could be covered under warranty, since I brought it in for the same problem nearly a year ago, and it was never corrected. My theory is that the problem went away over the summer with warmer temps and dryer conditions. It has been an intermittent problem and seems to be worse when it's cold/wet.

 

After getting the car back, the gauge seemed to function correctly for a couple of days and the check engine light also went out. Presumably draining the water out and possibly disturbing the connections might have helped. However, a couple of days later, with more precipitation and severe cold, and the problem has returned.

 

The service adviser said he'd talk to Ford to see if they'd cover this repair, since I'm now out of the b2b warranty. It's been a week and I haven't gotten an answer.

[mwr]

I asked if perhaps this could be covered under warranty, since I brought it in for the same problem nearly a year ago, and it was never corrected.

I wouldn't take "no" for an answer...

[Texasota]

At least you now know what is causing the bizarre behavior. That is good news.

[md13ffhguy]

I wouldn't take "no" for an answer...

So, two weeks later, my service advisor calls and says Ford has offered $300 towards the repair. I, lacking the energy/will to fight for more, call it a fair deal. Part(s) are on order. Edited March 8, 2016 by md13ffhguy

[Texasota]

So, two weeks later, my service advisor calls and says Ford has offered $300 towards the repair. I, lacking the energy/will to fight for more, call it a fair deal. Part(s) are on order.

Roughly 50% covered by Ford. Seems reasonably fair. Best part is you now know what was causing the problem and will soon have a fix.

[md13ffhguy]

Update: Waiting for the dealer to contact me to say the part has arrived... Been close to a month, I guess.

[md13ffhguy]

Still waiting. Are there any Ford reps on here anymore? I tried PMing FordService a while back and did not get any response. Still love the car, but it really sucks driving around with a fuel gauge that seemingly displays anything but the truth. I'm lucky to have not run out of gas yet, although it seems I may have come close a couple of times.

[ptjones]

Still waiting. Are there any Ford reps on here anymore? I tried PMing FordService a while back and did not get any response. Still love the car, but it really sucks driving around with a fuel gauge that seemingly displays anything but the truth. I'm lucky to have not run out of gas yet, although it seems I may have come close a couple of times.

If you put in 14 gallons you very close since the tank actually holds 14.1 Gallons. I ran the tank dry just to find out. :)

 

Paul

[murphy]

The FordService rep is no longer here.

[Hybrider]

Supposedly you should be able to go to their Facebook page to contact them.

[md13ffhguy]

Btw, my car was fixed a couple of weeks ago. I paid $300 and Ford covered the rest, despite now having about 65k on the car. The gauge has been fine since the connector was replaced on the wire harness coming from the fuel tank. Hoping the problem doesn't eventually repeat itself.

[Texasota]

Btw, my car was fixed a couple of weeks ago. I paid $300 and Ford covered the rest, despite now having about 65k on the car. The gauge has been fine since the connector was replaced on the wire harness coming from the fuel tank. Hoping the problem doesn't eventually repeat itself.

Good deal. Hopefully that was the problem and it will not return. I've been trouble shooting a problem with an HDTV and finally isolated it to a bad HDMI cable. These kinds of electrical intermittent problems are frustrating.