I got my fuel pump recall-replaced a few months ago. Before they sent me the recall notice, I'd often drive it to empty on interstate trips, and it would reliably have ~1 gallon (40-ish miles) left in the tank when the gauge showed empty and the remaining estimate was 0, so I'd drive it until the dash warning came up with the "critical power system failure" message and it switched to battery power. Today I thought I'd do the same. But, now it didn't even get to 0 before being actually empty. It was around 30 miles remaining range estimate, and 2 bars on the gauge, when I got that "critical power failure" and it started using battery power. Has anybody else seen this with the new fuels pumps? Is it possibly something to do with the replacement pump, or did the dealer eff something up when they replaced it?
Just wanted to give you some type of reply. Short answer "I don't know" and I'd guess most of us don't. I'm re-wring almost my entire reply. I didn't realize the fuel pump impeller recall (which I did do) isn't the same as a cracked fuel pump which can be related. But yeah, if you have a cracked fuel pump you'd be losing fuel which is likely a dangerous condition. I presume you'd also be able to smell gas leakage. Short, I really don't know much about it. I would not be concerned about any mpg loss in and of itself, but I'd be *very* concerned if its leaking, and if that's the reason for mpg loss. One would hope if that's the case there would be strong secondary indications -- smell of gas.
It's not losing fuel or MPG. It's just got approximately a gallon left in the tank that it suddenly can't reach and brings up the warning. I see bars on the gauge and HV miles remaining estimate of about a gallon when it happens. Before the recall, I'd often rely on there being a gallon left in the tank when it hit 0 gas bars and 0 HV remaining for knowing when I needed to stop for gas. I'd just drive it to "empty" then stop at the next gas station. It still wouldn't be actually empty at the point, just it'd think it was by the gauges but not by the generator system.
Sorry I misunderstood the question. Hopefully someone out there has a similar driving profile to you and can give you some information. My own situation is 100% electric commute, so there's no reason not to just leave the tank full most of the time.
It’s possible, but not likely, that the fuel sender was physically altered. There’s a float on the end of an arm that swings up and down through an arc as the fuel level rises and falls. It outputs a signal in ohms based on the position of the arm/float. The range of resistance (ohms) is mapped to correspond with Full and Empty on the fuel gauge. If the arm is bent or if the position of the float on the arm has been changed it will produce inaccurate results. Alternatively, the mapping may have been reprogrammed to deter less then desirable behavior by vehicle owners.
So they say they've tested the pump and replaced the "sender" to no effect, and verified that the tank really is empty while it is showing three bars remaining. Any other thoughts I may be able to pass on the the service shop?
From my experience service shops, especially dealers, do not really care for customers telling them to do things a certain way. That being said, the problem lies with the fuel level sending unit or float rod. Maybe they need someone more qualified to look at it.
So they claim that replacing the "sender" supposedly fixed it after they emptied the tank, refilled it, emptied again, then refilled once more. Granted that means they helpfully filled up the tank while doing so, so it will be a while before I can run it to "empty" on HV mode again and see if it is actually fixed for myself
