intermittent, but frequent, loss of ICE power at wheels (2007)

alrighty... so.. the inverter coolant level is definitely low.. a bit below the Low line. It does appear to be experiencing motion in there, but it's beyond my ability at the moment, to discern if that is simply from the engine vibrating, or from the system working as it should. i'm going to load it up to the full line and see what happens.

Code result: The code for P0A93 is gone. I know it was there last time we had the problem inspected by a shop, in November. Gone now. Car was driving weird today, though not as awful as it is some days.

Current codes: P1116, P1121. P1116 appears to be gas engine coolant temperature. P1121 appears to be Coolant Flow Control Valve Position Sensor Stuck.

 

I hate to continuously bump my own thread, but I'd like to make sure that if people who helped or are interested, subscribed to the post, then they'll get my updates

- Checked engine coolant. Absolutely full up. That slightly worries me, because I can't recall having ever serviced it, perhaps the guys that do the regular tire rotation/oil change maintenance top off the engine coolant.
- Loaded up the inverter coolant reservoir to the full line. I can now *hear* a slight liquid sloshing when I switch into "Ready" mode. I'll check it tomorrow to make sure that it stayed up there. (is it possible that it may need to get reloaded, as it might suck some into the system, thereby appearing low again tomorrow? or does it not operate like that?)
- Checked codes. Previously mentioned P1116 and P1121.
- Reset/Cleared codes.
- Kept my scanner up and running, and checked out some data while the other half drove it about 10 miles to school, then i drove it back. Engine Coolant temp rises rapidly to 190deg, and then backs off to about 182 or so. Doesn't get higher than about 192-193 occasionally. Is that correct coolant temp range? I didn't see any selections in the menu of the tool for hybrid diagnostics.
- The other half says she thinks it may feel slightly more powerful, but is not sure, she doesn't entirely believe that there's a problem beyond the crappy gas mileage. Which she thinks is because of the cold weather. She's not the most attentive to things changing. lol
- For my drive back home with it, it felt quite a bit more powerful, pretty much back to normal, except at the highest RPM, it doesn't feel like the engine wants to go full out. Close, but not quite. What the gas engine is giving, though, it feels like it's ending up at the wheels now.
- Checked codes again, it says the P1116 and P1121 are "pending", but not active. So, I guess that's good? if they remain that way, right?
- I'm going to drop another 60 mile drive on it this evening, and see how it goes.
- If this car survives the next week or two of 4 different adults depending on it all over the entire metro area, I'll be impressed.

 

A couple of reasonable drives at close to regular power is promising, but by no means indicative of anything being fixed, maybe it's just being less intermittent by sheer will of the universe making this hard to diagnose.
Yeah I think I saw something for PIDs, I'll have to look into it. Probably be a good thing that I wrote dashboard software that interfaced to OBD-II once, so I should know something about it

I turned on the Average MPG view once I got onto open highway, and was able to hit over 40MPG while running at 70mph for several miles. That's a whole heck of a lot better than it has been in months, although prior to plugging in this scanner i only had the built in MFD to go by, so it's not really apples comparisons. But I'm slightly optimistic.

What has me most optimistic, is that I tested several times flooring the accelerator on the highway, and it actually accelerated every time, instead of revving the engine way up and not accelerating. I didn't feel like the engine is at 100% power, but it was definitely putting ICE power to the wheels, without spinning freely.

Oh, yeah, P1121 came back, but 1116 is still listed as pending. Engine coolant temp never went off the 183-193 range after it got up there the first time.

 

OK, All, here's all the bad news now:

Despite having a few good drives the other day, there's literally no change. Today, I checked all the fluid levels before starting, started it up, let it sit for about a minute (it was still quite warmer outside than expected, so I did not let it sit for very long), hopped in, turned on the code scanner app, and saw that the P1121 code had returned to Pending status on it's own, and the P1116 code remained pending as it was the last time I checked. I also checked that the inverter pump seems to be working (can see fluid moving when car is Ready . . . before it turns the ICE on..)

Drove it out of the driveway, put the accelerator down approximately half way, the engine revved way up, and the car started moving forward, very very slowly. I released the accelerator, as the engine revved back down to idle, I put it down to the floor to see what would happen. The engine revved up to full tilt, and the car continued accelerating very slowly.

I was getting very very close to 0% power from the engine to the wheels. I had to get where I had to be, so I took it's slow acceleration, and got there. On my way back, the engine coolant finally got up to the 190 range, and it started to shut the engine off at stops, like it should. The first time I tried to put the gas down after the engine stopped, it started to take off like it was going to work perfectly, and then suddenly, it felt like something released, and the engine revved way up, and i wasn't able to accelerate (much) anymore.

It was intermittently working again on the rest of the drive home. It almost seems like it's something that occurs much more frequently when cold, versus when hot -- but that could be entirely coincidental. My drives throughout the week are ranging from 10 to 40 miles at a time, and the car is in regular use. During the weekends, my drives are just a couple of miles at most, usually. HOWEVER, on Thursday, when it was unseasonably warm, I *also* did not let the car warm up any significant time before driving it, and it acted perfectly.

I am at a loss for any ideas at this point. It still *feels* like some kind of mechanical failure between the engine and the rest of the car, but I'm no closer to an answer than I was before, it would seem -- it's doing the exact same thing, still intermittently, but now there's no active codes.

On the bright side? we're going to have unseasonably high temps for the next week it seems, so maybe it'll be better? maybe if we have some ideas, i at least won't have to freeze while checking them out? :-D

Any further thoughts or ideas?

 

Engine is definitely starting, and running. Revs with the gas. Doesn't introduce much if any power to the wheels, though.

 

Hi Chap, thanks for getting back.

It's a generic ELM327 reader, currently using an Android app called "OBD Car Doctor".

I suspect that I may have possibly not been getting the P0A93 code, at this point -- It may be the P1121 and P1116 codes that have been recurring over the years. I am 100% positive that our regular mechanic shop had told me "Hybrid cooling system", back when we got the car, and I may have just assumed that it was P0A93 from the descriptions here . . . which leads me to ever since then wanting to be absolutely 1000% sure of everything that I say before I say it. :-S because I think I may have lied by having convinced myself of something that I wasn't 100% knowledgeable of.

Right now, there are no codes set Active, no dashboard warnings. The P1116 and P1121 codes are listed as Pending.

I've occasionally thought I got a slight wiff of antifreeze smell, but I don't think I've ever smelled anything else coming from the car, that I wasn't able to blame on another vehicle nearby.

Know of a good Windows diagnostic app? I'd probably find it a hell of a lot easier to deal with my laptop for heavy work rather than my Android. I haven't played around with the app more than what it comes preloaded with, so just the "Read Diagnostics" and some of the "Popular" monitoring tabs on it. I can't tell from the other posts in the forums, if Techstream will work with an ELM.. some say it does, but it doesn't look like anyone's actually sure of it. :-D

 

I had to take a real short highway run today, i got off the entrance at about 50mph, tried to put it to the floor to catch up with traffic, and it just slowly inched upwards in speed, with the engine going all out.. not cool... and then suddenly just as i got to about 60, it "caught", and accelerated like a bat out of hell to 70, and then went back to being a slug. I'm not smelling anything out of the ordinary. I've blown up a couple of clutches in my years, so I've definitely smelled that, but I'm not sure I'd recognize the smell as specifically as I do other car smells, like antifreeze and brakes.

 

It's a bit difficult to say, because I am clearly getting the full power of the electric motor when starting from a stand still. I can actually get a tiny chirp out of the tires if i put it on the floor from zero. Once it gets over about 15-20 is when I can really feel that the engine is revving up, but the car isn't accelerating faster. Perhaps if there were a way to completely disable the electric, then I could get a better handle on it. It'd also be really nice if there were a driving mode that would just use the gas engine as a generator for the electric system, since that's basically what I'm getting right now.. except it's throwing my mileage totally to crap because the engine is sucking up so much fuel that i'm not getting much return on, when it revs out.

 

Yeah, part of the question about software, involves "Does Techstream work with an ELM327"

I'll see if I can load it to my laptop and come up with anything useful.

 

ok, not sure if this helps.. closest things i was able to locate in the list of things that i could tell it to record, i grabbed... Battery (turns out that's the 12V not the hybrid.. yawn), Throttle Position, Absolute Load Value, Relative Throttle Position, Calculated Engine Load Value, Engine RPM, Engine Coolant Temp, Absolute Throttle Position B, Accelerator Pedal Position D, Commanded Throttle Actuator, and Accelerator Pedal Position E.

looks like it spit me out a CSV

I went to the floor on every acceleration in this CSV. The second to last one, the car seemed to be running correctly, and the last one, i didn't have enough space to get into a speed range that would give me any idea if it was right. The first several, it all dragged like a slug on.

I'm also picking up this "Hybrid Assistant", though I don't see what that might offer as far as diagnostic. Then I'll check out Torque, I guess. Becuase I did more looking into Techstream, and it doesn't seem like anyone's figured a way to make it work with ELM.

... edited to add a zip with the CSV file...