fuel pump? code #3190

Was idling in my driveway to work on the AC, shut down, took the gauges inside, started, drove 2 blocks and red triangle of death lit up and the car coasted to a stop. Traction battery showed depleted. ABS and VSC lights also on.

Was extremely hot-102F and car had been sitting in the sun.

I messed around for a few minutes and retried and it started right back up. Drove home, engine was boggy. Came out a bit later and it restarted and drove to the grocery store just fine.

Code was just #3190- poor throttle response.

The way it went out and came back says fuel pump to me. However, the fuel pump appears impossible to replace. No auto parts store carries anything. It's not sold except as with a whole new gas tank from Toyota, over $2K in parts alone. That suggests to me that this might not be something that actually gets replaced?

I don't know, I'm gonna check the 12V battery to make sure.

 

Hmm I checked the 12V battery. Normal resting voltage is 12.6V, and it's super hot out now- which raises the normal resting voltage of an agm battery higher.

I got 12.2V. That's suspect. When it died, I did see the VSC and ABS lights come on too. That's a bit questionable- I wouldn't automatically expect those to light up if the engine had no fuel pressure.

I DO know that when this battery died a few years ago, the dash went absolutely crazy when I tried to start the car. Everything flashing on and off, even the drive position cycling through park, reverse, drive, as various pumps clicked on and off and made dramatic whining noises of varying pitch.

The fuel pump can't be replaced except with the whole tank, and the tank set is over $2K for the part alone. Nope, not something you can lift the rear seat and pull out, not in Gen2 apparently.

The starting battery is over $250, and was replaced only a few years ago, but it is in Texas heat, with the "extra" ABS/VSC lights when it died, and seeing only 12.2V on it now- ok, yeah, I'm warming up to thinking we need to replace the starting battery first.

This may also somehow explain my air conditioning kicking out while driving, despite having good pressures, which showed up a few days ago. If system voltage was going low, that could cause the compressor to choke.

 

Well, I found the battery was under warranty, under 2 yrs old. I did put a charger on it this morning after finding 12.2V on it.

However, I put the MFD into diagnostic mode and went driving around the neighborhood, and the battery voltage remained a solid 13.7V. I don't think this is going to be a warranty replacement.

The 2009 Prius fuel pump (220K miles on this one) is a huge problem if that's what's wrong. Yep, it's integrated into the tank and bladder and cannot be replaced, you have to remove the whole tank. >$2000 part. Labor would be pretty high. I could do a junkyard pull, but that may be beyond my capabilities. Esp since it's over 100F outside. This could be reason to scrap the whole car rather than try to fix.

And I don't have solid proof it was the fuel pump. It did this ONCE. It scared me because it gave zero warning. Traction battery got depleted as normal, tried to take off from a stop sign, it tried to start the engine and failed, threw the RToD, engine stopped, traction battery already drained. And with the traction battery drained, there's very limited window for diagnosis before the ECU's restart attempts make the traction batt go totally flat and create an additional crisis. Filled up the night before, it has gas. If this happened on the expressway going to work, even if it starts up fine a few minutes later, bringing the town to a standstill is pretty serious. That's most of my drive, there's nowhere to pull over for much of it.

I don't see what to test further, if it's not misbehaving at the moment. I wouldn't be surprised if the fuel pump developed normal pressure until it drops out again. I went through the sheet SFO gave. It didn't actually throw a code for the engine failing to start, just poor throttle response, even though it quite definitely died but came right back and ran fine. So I don't think MAF is dirty, that wouldn't just stop the engine out of nowhere and then go away. Sudden stoppage then working fine keeps screaming "fuel pump" to me. Searching PriusChat for code 3190 seems to have a high correlation with fuel pump, but it looks like few people even tested that theory due to the incredibly high cost.

It was immediately after some really unusual conditions- extreme heat, and prolonged idling while working on the AC system. But I don't see how that would explain the symptoms, nor does it seem likely I could recreate it to better troubleshoot it. The only other factor is the low battery voltage (12.2V) this morning but the battery is looking ruled out so I don't know.

Normally I'd be out poking around more, but it's really REALLY hot out there right now. And if the fuel pump wasn't so crazy expensive and labor-intensive I would have already moved to replace it.

I have Torque and Dr. Prius app. I don't have Techstream. Any suggestions on next steps? All I can think of is drive it until it throws the code and check the battery voltage. Or throw $50 at a Techstream reader and some $$$ for a temp subscription to Techstream.

Taking it to a mechanic for diagnosis, is this likely to be productive? Seems like they'd do similar guesswork if the problem doesn't reoccur and likely guess fuel pump too, but fuel pump is too expensive to do based on a hunch.

 

And is there any additional theory that I could work on that explains why the AC stopped working about the same time? I don't see how. It's blowing 35C air. When I first started it, I saw it get to 20C at the vents but then the compressor shut itself off and vent temp shot right back up. I see it start to try to restart- temp dropped for a few seconds, but only a few deg, then gives up and shot back up again. Seems coincidental. The 12V starter batt, if failing, shouldn't do that, and the 12v batt seems ruled out for now anyhow.

 

Interesting. I did have the RToD a year or so ago for inverter coolant pump failure. Replaced with OEM.

So the ICP is new and a reliable OEM, and no code for ICP fail. I wonder if it has an unusual silent overheating fault because it was like 108F here?

Been driving the last couple of days with no prob from the AC.