Ok, so I may have buggered things up slightly - trouble code help!

So I've been fooling around with our school's Prius trying to map out how it splits regenerative and friction braking, and I've hooked all my equipment up to it only to turn it on and have it scream at me for touching its insides.

The P3000 code comes up as soon as I hit the power button, and then less than a minute after that, the C1259 code (HV regenerative system malfunction) comes up, followed by the C1310/156 code (HV system malfunction). At the same time, the radiator fan turns on and stays on until I power the car off. I've checked the reported SOC of the HV battery, which starts at 10% when I turn the car on, and I can watch it drop to 8% in a matter of a couple of minutes or so.

What says the brain trust on this? Do you guys think that C1259 and C1310 are also because the SOC is so low as to not enable to engine to turn over, or are they unrelated?

 

Thanks Patrick, that was my first step. Disconnecting the monitoring equipment cleared a few other DTC's (relating to brake pressure signals I was monitoring) but the ones I mentioned above are the remaining ones. I also installed a fresh 12V battery yesterday, as at an earlier point the car wasn't even reaching the ready state (the fresh battery solved that problem, and now it's just these 3 DTC's that I need to figure out how to get rid of). These DTC's are persistent and repeatable.

 

Update: I gave the traction battery a quick (and dirty) charge out of the car just to get its SOC up to engine starting range. After this charge I put the battery back in the car and started it - it seems there are no error codes (I didn't have time to hook the scangauge up to it to double check, but no dash lights turn on), but the engine refuses to start at all. You can hear (and feel) the computer trying to fire it, but it refuses to take hold. The car moves under electric power just fine though.

In answer to your questions - the car was working fine prior to instrumenting, but was last started some six months ago. I didn't add anything to the hybrid vehicle ECU loom - the only loom I spliced into was the skid control ECU - and I successfully road-tested the vehicle after splicing into this loom. Interlock is always engaged.

 

ideally - yeah a specialised NiMH charger would be the way to go. The Toyota charger is special because it has preloaded charging profiles for the NiMH cells, and plugs into the battery computer to monitor temperature change over time and voltage change over time.

If you've got nothing to lose, connecting the battery to a garden variety high voltage power supply is an effective way to resurrect a dead traction battery. You have to monitor dV/dt and dT/dt manually, and adjust charging current to suit, and if you don't know what you're doing (and even if you do) there's every chance you'll blow up your battery. But if you're otherwise staring at a $2000 paperweight anyway, there's not a lot of reasons why you shouldn't.

For reference, I used a charging currents varying between 0.9A and 1.5A for a total of 3.5hrs charging time, and had a blower fan situated next to the battery at all times. I relied on dV/dt to adjust charge current as casing temp changes were negligible. Battery voltage started at 197V, peaked at 214V, and the charging process was turned off when dV/dT went negative (final reading 212V). In total, I added about 0.85kWh minus battery losses (which I guesstimated were around 20%).

Anyway...I still have no idea why the engine isn't starting...though it might be because I need to take the fuel rail off and give the injectors a good cleanout. It has fresh fuel, but I'm not sure if thats getting to the fuel rail, because it's a returnless system.

 

Yeah I bought the mongoose interface and the techstream software seems to have somehow made itself available to me. The only DTC's it comes up with at the moment are an airbag one (because I have no passenger seat installed), and an air conditioning one (because a temp/light sensor (I forget which) is defective).

I took off the fuel rail just now and evacuated all the old fuel that was in it then put it back together. No change, no engine firing, and no DTC's!!

Just a thought - in the process of instrumenting the car I took apart the large orange 3-phase conductors that run from the inverter to MG1 and MG2 (to slip current transducers over each phase). Supposing when I was putting the conductors back together for MG1 (i.e. the one that isn't the traction one) I accidentally swapped around two of the phases...would that cause a non-starting engine, electric only running, but no DTC's? I have a sneaking suspicion that I might have done just that, but I'm really not keen on taking that plug apart again.

 

Seilierts might be right. I was only using a small analogue voltmeter to measure terminal voltage and graduations are at 5V increments, so it's entirely possible that I misread a negative dV/dt when there was none. Also, it was 6:45pm on a friday night and I was itching to get the hell out of here, so I'm inclined to think I didn't charge it a helluva lot. That said, I did charge it enough to drive the car around the parking lot at up to 40km/h, so instinct tells me if it can move a car at 40km/h it can sure as hell start a weeny little 1.5 4cyl.

Seilierts - oil is fine, ECU wires are fine (checked these). Don't have a fuel pressure gauge to check fuel pressure but the pump is easily flowing enough (did a flow check), and not sure how to check spark on these things (I'll have a look thru the manual). I might pop the traction battery on charge a little longer (it's dropped down to two bars on the MFD because of all the driving I've done engineless). But I'm inclined to think my problem is either fuel-related or possibly because I swapped a couple of wires around the MG1 power cable.

If anyone can tell me how the wires are ordered between the inverter and transaxle I can double check this, as I can't find a line drawing or exploded diagram of it anywhere in the workshop manual.

Thanks everyone for your very helpful discussion so far!

 

pEEf - The car doesn't try to crank the engine at all when cold. When I drive electrically, I get smooth acceleration going forward, with sometimes a small hesitation here and there (the same sort of hesitation you get when it fires the engine up, but alas - no engine) but interestingly in reverse the movement is extremely jerky. All this, and no fault codes.

 

Seilerts, Techstream is definitely working fully (not in generic mode), I just double checked. I've charged the traction battery again, this time terminal voltage was 237V. This didn't change the car's behaviour, but I know there's definitely no P3191 code there. I did notice though that even while the car is in park, the front of the transaxle casing, the inverter casing, and the big orange power wire that runs between the two (at the front right hand corner of the inverter) got quite warm to the touch. The battery also dropped SOC quite quickly even though no accesories were on. The plot seems to have thickened...

PS - pEEf - I leave the 12V battery disconnected normally, and only connect it when I'm troubleshooting again.

 

Does anyone know which ECU I need to access to find the engine crank active test? I looked through all the active tests I could find in techstream and couldn't find that particular one at all. Is the test actually listed as "Engine crank"?

Drew, I'm at UTS. Are you nearby? I'd be happy to give you a demo of techstream (though I don't think I've really played with half the stuff it does) - once I have this damn car working!

Thanks pEEf, very much appreciated - I'll record the file and send it to you tomorrow when I'm back at work.