Mountain Climbing slowed to a grinding hault.

Are you using 85 octane in high altitudes?

 

Hi kueker. Did you happen to notice anything unusual going on with the SOC (8 bar battery display) during the event?

 

Regular Unleaded Fuel in the Rockies is 85 octane. Premium is 91.

The "protective mode" is not a mode, it is just part of the normal algorithm. And it does not speed limit, it power limits. When you climb a large hill with a heavy load like on I-70, your SOC will drop to 1bar. This will basically power limit you to only ICE power still heading up a big hill, and will slow down unless the continuous required power is less than the maximum ICE only output.In your case it was not, so it slowed until it equalized. Now it should not slow you down to 0 as you can climb rather steep hills on engine alone with a pretty good load inside, albeit not fast.

Were you effected by the stalling recall in 2004/2005 models way back when? Did you get it done?

Any lights on the dash?

 

Mountain driving is really hard on the battery, especially if you do not use B on the downhill, most especially in an older battery. You might think it is neat to put 8 green bars on the battery meter, but with a fully loaded car going down a steep grade, that battery is going to charge fast and heat up. Then you turn it off at the bottom, but the heating continues, due to oxygen formation and recombination as part of the charging process at high SoC levels. On an older battery, that charging level is much closer to full, due to a mismatch between the Coulomb counting SoC algorithm and the loss of capacity on an old battery.

Later, get back in the car, turn it on, the battery fan spins up to high because it has overheated. It is quite likely that the SoC calculation is very confused as well. When I have had this happen to me, aside from that pants-crapping feeling, I have watched the SoC plummet in spite of standing still. We have seen other cases where SoC overshoots on the low side as well, 29% according to one user's ScanGauge. At this level, you can imagine that the HV ECU has decided to charge the battery regardless of the current power demand from the gas pedal. Now, slowing to 0 is a new one, but going much slower than expected can definitely happen under particular circumstances.

Anyway, long story short, your old battery overheated somewhat, it is a sign of wear, it does not necessarily mean that it is about to die, but do try to avoid parking it and turning with more than 6 bars on the battery meter during the summer.

 

Yes, the OP's story is interesting I've never heard of this before.

IIRC, I've seen my HV battery SoC get as low as ~35% before per my SG. That's really unusual. I don't recall if it was during a hill climb or while I was in >100 degree weather in Vegas w/high AC usage.

 

It could be the gas, it could be your air filter (don't forget to check the easy things), it could be the HV battery issue mentioned here, but it could be other things as well.

In another thread on maintenance I remember people discussing spark plug changes. The consensus was that you didn't need to change them before the scheduled maintenance mark (120,000 if I remember correctly) but someone mentioned the part above the plug failing (a quck google search tells me these are called "ignition coils" or "spark igniters".

Ah yes, it was "FBear" at http://priuschat.com/forums/gen-ii-...bleshooting/20246-spark-plug-replacement.html saying "...the individual coils on top of each plug, which I sadly discovered have a high failure rate due to the excess heat under the hood."

Apparently there was a TSB about water leaking into these causing failure which "Patrick Wong" mentioned in http://priuschat.com/forums/gen-ii-...g/45550-ignition-coil-getting-burned-out.html

Several people have described this diagnostic technique:

if you unplug the coil to find out which one is misfiring, you'll probably find that 1 will not change the effect. however.. if 1 isn't firing and you unclip another, the prius will shut down and error code for an ignition coil being unplugged or harness unplug.. depending on how you do it.

but Patrick says "there is no reason to replace the igniter unless you have a misfire DTC and have determined that the igniter is at fault, or if you see burn marks or rust deposits on the plastic body of the igniter."

and ignition coils/spark igniters aren't a due to be replaced on any mileage or time base.

So I can't say that your plugs or ingiters are at fault but you could grab a code checker ODBCII scan tool and see if you have any codes. It might even be worth pulling the plugs to inspect and make sure the ignition coils look normal while you are at it. You may want to put fresh plugs in if you pull the old plugs since the plugs are a low cost item and you'll have already done the work.

But before I went there I'd rule out the air filter as it's even cheaper to replace.

 

Thats the worst scenario for a Prius. Its really its only drawback. Fully loaded car and steep hills and not being aware of the state of charge of the hybrid battery.
When the car starts losing power its because the hybrid battery is almost discharged. One purple bar. At that point the mg2 becomes an albatross around the cars neck because now MG2 demands power and now the hybrid battery is dead and can't really power it so the Inverter must do it full load & now the little engine has to supply almost full power with little contribution from mg2.
Our car is a mutt without MG2 contribution.

If you opened the hood when you pulled over you would have probably notice the Inverter and the Inverter coolant reservoir was wicked hot and I bet so was the cvt. That scenario is super duty for a Prius.

I hope you have fresh cvt trans fluid in the car and fresh Inverter coolant. If not you should have both changed asap.

If it was me I would not attempt that trip unless I had fully charged
hybrid battery and a good running start speed wise approaching the worst hill. Take it very easy and the second I see the soc go purple pull over for a cool down and a forced re-charge. Any other way and your just beating the hell out of the car.

 

Put the car in drive, press firmly on the brake pedal, and depress the gas pedal about halfway until you see green arrows flowing to the battery. Do not do this if you have more than 5 bars on the battery gauge, or if you can hear the hv battery fan running at its highest setting.

 

You can force charge all the way to 7bars, any time. You just need to keep re-adjusting the go pedal pressure as the car readjusts how much it wants to run the ICE versus MG's.

Not really a good thing to do, but there are times when it comes in handy.

 

What service did the dealer perform to produce flying colors? Your way way overdue for cvt fluid and inverter coolant change. If your hoping to get 250,000 on it you have to change the fluids. Your cvt fluid is black. Get a sample of the cvt fluid and send it out for an universal oil analysis (UOA) like alot of us have. I sent mine here:

http://www.wearcheck.com/

It costs $25. It will give you a real good insight on how hard you are on the car.
BTW, it wasn't a mysterious incident. It was just the hardest you ever pushed the car.