ICE rough idle/dies, battery won't charge, triangle of death...

I had a similar issue a couple of months ago with the engine not starting. Sometimes it would start for a couple of minutes and then stall followed by all the warning lights. It turned out to be the coolant switching valve for the thermos. $70ish from Toyota. 30 minutes to install if i remember right. Take it to your local parts store and have them check the codes for free.

 

Yes, get the codes read. Nothing to do until then. Get the "mini VCI" on eBay if you can.

If the engine won't stay running, with rough idle, then the fuel system, air intake, or engine ECU is more likely suspect.

 

Whats all the fluids look like under the hood?

Oil?
Engine Coolant? If white plastic engine overflow reservoir is empty open the rad cap by taking off the top black plastic valence cover and check the rad level. If low either place you have a leaking engine water pump.
Inverter Coolant?

Car supposedly had ICP recall done but that doesn't mean that pump didn't die. It's a pretty high fail unit. Put car in ready and take cap off I Coolant reservoir and look for good turbulence in that reservoir.

 

A stumbling engine can be the tip of the iceberg, with many possible causes lurking below. Get it diagnosed.

Just thinking of the first time I set up valve clearances on a previous car. I mixed up the intake and exhaust clearance values, the engine wasn't too happy.

 

James, it seems that the root cause of your problem is something causing a loss/reduction in engine power rather than a battery or inverter problem. When the engine problem occurs the traction battery is providing most of the motive power and is therefore being discharged.

When this happens you should try to stop before the traction battery gets too low. You'll need to have traction battery charge available while the engine or fuel problem is being diagnosed/repaired.

 

You can also remove and examine the spark plugs for deposits and other signs of abnormal engine function. I bought my 06 gen 2 with 180k miles and found significant hardened deposits on the plug electrodes (apparently they had never been replaced or cleaned before)...I replaced them with new iridium plugs and the engine ran much smoother.

May be a good idea to check the throttle plate and MAF to see if they need cleaning...it's a fairly high milage vehicle and if the throttle body has never been cleaned there could be quite a bit of gunk in there.

 

The ScanGuage II can read the prius codes. Mine diagnosed my HV battery failure instantly.

 

If you have the triangle, there are codes.

 

Did any warning lights appear besides the master warning triangle? If yes, pls. provide sharp photos.

If the master warning triangle was the only warning light that appeared, there may not be any DTC logged. For example, you can make the master warning light turn on by shifting into D and opening the driver's door. Or if the engine oil level drops down, the master warning light may appear. However in either case no DTC is logged.

If the shop is not a Toyota dealership or a Toyota independent specialist, then the mechanic may only have a generic OBD-II code reader. That will pick up DTC logged by the engine ECU but probably will not pick up DTC logged by other important ECUs, for example the hybrid vehicle, traction battery, and skid control ECUs.

Or, if the 12V battery is weak or near dead, most of the ECUs may lose any logged DTC. The skid control and SRS ECUs have nonvolatile memory but the other ECUs depend upon constant 12V power to keep their memory alive.

 

Good call Patrick. I forgot about this, but actually remembered it last night when i tried to put my car in reverse with my door open.

 

If this DTC returns, you have a problem with the throttle control motor.

That light comes on based upon a timer in the odometer which needs to be reset at 5K mile intervals. The light is simply reminding you to have the engine oil and oil filter changed. There are several posts about how to reset the timer after the maintenance has been performed.

 

You don't have to monitor any functions unless you see warning lights appear. At that point, take good photos of the warning lights, and make a note of any DTC that are reported.

If the DTC is P2102, then you should clean the throttle plate and throttle shaft using throttle body cleaner, then clear the DTC. If it comes back yet again, then you will need to replace the throttle control motor.