2005 Prius - P3190, P3191, P0A0F

I’ve been having these problems for about 18 months now.

My last post can be found at 2005 Prius - 12V battery keeps dying despite repairs/replacements | PriusChat

Since I’m sick of going to the dealership every time this happens, I’m drawing from my scientific instrument repair experience and doing this myself. I figure if I could repair an x-ray photoelectron spectrometer and an HPLC then I could take a good stab at this. I bought myself a 12V battery recharger/tender/reconditioner and a Mini VCI cable with Techstream so I can read the codes myself.

The most recent event happened in November and it took me until last weekend to get the Mini VCI cable to work (ultimately found out the wrong drivers were given to me). It’s not like I’m going anywhere these days so this project was able to be left on the backburner.



November event:

Problem: Gas engine cuts out (again). Luckily, I’m close to home and manage to limp back. When I try to restart the engine, it has a fast idle for about 15 seconds before dying again. I’m able to do this a few times but now it’s locked into only allowing me to switch between park and neutral. In retrospect, I might’ve just been cranking the engine and draining the hybrid battery but I can’t be sure.

12V battery was found to be drained again. I put the recharger/tender on and brought it back up to spec. I found a 130 mA parasitic load on it – since I hadn’t driven for a couple weeks and the grocery store is only around the corner I guess that was enough to drain it.



This past weekend I finally got Techstream to work and I used the software to grab the codes off of the car:

Engine & ETC:


P3190 – Poor engine power

P3191 – Engine does not start

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Hybrid Control:


P0A0F – Engine failed to start

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Thankfully, the HV battery doesn't report any codes:


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Under the P3191 code is a more detailed report giving the parameters that are off spec:


I'd be grateful if any of you can help me understand what these off-spec parameters are pointing at as the issue.
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The last time I went in for this problem, they cited technical bulletin EG047-04 which instructed them to update the ECU so that the computer would allow the gas engine to crank some more before giving up.

From what I recall, if that didn’t work then the next step would be to inspect the air intake and the throttle body.

I opened up the air intake and took a pic of the throttle body. There’s definitely some residue but not as much as I’ve seen in other posts:

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I figure my next steps would be:
1) Buy some cleaner to remove the residue on the throttle body
2) Get a new engine air filter – there’s some crap in there, might as well
3) Replace the 12V battery (optional? recommended?)

Do you have any recommendations/thoughts about this problem I’ve been having?

I’d like to keep this old friend of mine going for another couple years if I can. I’m not ready to let go yet I guess.

 

Acknowledged. I suppose I'll do as much as I can and document it the best I can before handing it off to the professionals then

 

Updates:

I got a better look at the MAF and it was dirty. I removed and cleaned it with some MAF cleaning spray and help from YouTube university.

The throttle plate had some varnish on it and I cleaned that as best I could with some carb cleaner and a cleaning cloth taped to a screwdriver. I also checked the movement of the valve and it didn’t feel stuck at all.


I did notice that I could see oil past the throttle - is this normal?

I used TechStream to clear the codes and fired up the engine. It ran but only for about 11 seconds.

I grabbed the codes and I still have P3190 (Poor engine power) and P0A0F (Engine failed to start) on there. I took screenshots of the details.



I finally gave in and had it towed in for service.

The tech called me back and said that there’s no pressure delivering fuel to the engine. Getting to the fuel delivery system is labor intensive and would cost about $500 to confirm the diagnosis.

Apparently for this model the fuel pump and gas tank come together as a unit and bottom line cost including labor would be nearing $2000.

 

Thank you for your insights! That was very helpful.

My family is pushing to have me take the car to an independent mechanic they all go to who said he could get the part for $700 and do the labor for $200, so $900 + tax. The shop is 80 miles away though, but AAA says they'd cover the tow. I don't know what the warranty on the work would be like or if they're even Prius-certified - I'll ask when I call them tomorrow.

As much as I'd love to keep my Prius I just don't know if I can trust it after stalling out on me 4 times in a year. It's shaken my confidence and now I don't know if I could, say, take my wife to the doctor or dog to the vet if an emergency happens. I gotta consider if I should do a trade in and get a Prius Prime or an EV from another company.