P3020 after battery work- Mod 10 service plug disconnect?

nah, dealerships don't do anything but install new oem packs.
i think you are being premature in your assessment. while there are many reasons why a prius can lose mpg's, i think you need to reset the trip meter and burn 10 gallons or so and see what the mpg calculation looks like at the pump.
not sure what is going on with your a/c, maybe needs a charge?
in the meantime, you can look at things like the tyres and pressures, all the filters, plugs, injectors, throttle body cleaning and etc. to see if anything else could be affecting mpg's.

 

My actuator constantly hisses every 10 secs. C1256. Hopefully it's not an issue until it becomes even more frequent (every 5 secs?). Replacing abs doesnt look easy.

At this point, everything that goes wrong in gen 2 has gone wrong.
1. Valve cover gasket
2. Inverter pump
3. Catalytic converter
4 Dashboard display
5. Hybrid battery
6. Spiral cable in steering wheel
7. Consumes oil. Put oil every 1200miles
8. 12v battery
9. Put in shield on CAT

And ABS pump hisses every 10secs.
Now 3-5 minute delay in starting AC s/t

 

hopefully, the actuator will hold out, but every 10 seconds is quite often. does it do it when the car is off?

 

Yes but only when driver side door is open. But hissing freq then is every 15 secs.

 

of course, the hybrid battery will have to work harder to run the pump when in ready, so thatwill cost some mpg's. not much i wouldn't think, but idk for sure.

 

Cabin air filter was very very dirty with small rocks, leaves , dirt , debris. This was likely causing AC to delayed start(5 mins?) & also overheated & damaged my old Hybrid battery?
Replaced the dirty cabin filter with new and also cleaned some dirt inside. Despite that the AC start is still delayed (4-5 mins ).

Note : this delayed start in AC just started happening a day or two before I got the red triangle & hybrid battery codes

 

That is nowhere near enough distance to determine if anything has improved. You also need to detail exactly what the process is you're using to determine the MPG. We cannot really comment unless we know these details

Easy enough to verify, but highly unlikely, unless by dealership you mean some shady 3rd-tier car lot. If you mean a bona fide Toyota dealership, then it would not be worth their reputation to do such a thing.

You have something wrong with the A/C.

Well, this on its own is enough to impact your MPGs.

 

How come no Code for AC?
And why does the AC come on after >5 mins ? This has been happening only since last week. What common AC problems are there for gen 2 Prius? Did the dirty cabin filter cause any issues (it's replaced now)

 

"No codes" for the A/C is likely caused by there being many possible faults that should be found and corrected by properly trained and equipped technicians.

Normal A/C diagnostics start with connecting a gauge set to check high and low side pressures, checking condenser fan operation, looking at A/C scandata for compressor function, etc.

Your brake actuator IS BAD, - right now. Whether you want to wait until it fails completely is up to you. The pump is running many many more times than normal. Normally, if you don't press the pedal, the car should go one or more hours before the pump cycles on.

Eventually something will stop working and you will (should) have "backup" mode where the pedal directly connects to the front brakes only - no boost, no ABS, just "pull over, stop, & call a towtruck".

Posted via the PriusChat mobile app.

 

AC seems to start sometimes within a minute. Sometimes I have to drive 3-4 mins for AC to start. Usually, it seems like it won't start using just the hybrid battery power. Inverter coolant still has turbulence...so unlikely it's inverter overheating issue due to bad inverter pump.
Once AC starts, then I off it and then press on. It instantly starts. Done this 20 times. No issues here.

It's only the initial AC start where it's randomly taking a few mins and I have to drive(most of the times)

 

Bad switch?

 

Which switch ? Any blown fuse causing it NOT to use hybrid battery power to start AC ?
9 out of 10 times AC won't start without driving for a few mins.
I don't know if computer still thinks it's the old Hybrid battery(which had low charge) and it is preventing it as a fail safe mechanism .

No code is displayed other than 21(solar sensor circuit) when I press ac, recirculation button on steering wheel and press power button twice

 

That is nowhere near enough distance to determine if anything has improved. It would help if you also detailed exactly the process you're using to determine the MPG. We cannot really comment unless we know these details

That's normal Prius behavior from a cold start. It actually comes on straight away, it just does not move a lot of air (hot or cold) straight away. You are only probably noticing now because your focus is more on the A/C

Not likely.

 

>>> Don't think so. AC in the display is still off. No air comes out as well. I never remember sweating it out for 5 mins like this ever before. Something is up.

 

Yes, that does not seem right. Even though it does not move much air, it still should show the A/C as being on.

You might need the services of a good Prius A/C technician.

 

i was thinking the ac button

 

AC seems to be starting ok now. The only thing I did was disconnect 12v(5 mins) to wipe out any memory it had (like hybrid battery overheating which may have caused it not start AC).

Mileage after driving >200 miles is still 38mpg. Before with old battery I was getting 41mpg.
Filters are good. Oil level is good. Tire pressure is good.
Also, note I never got p0A80.
Only got p3000, p3020
Also, until now battery bars has never gone to green. Mostly blue with maybe 6max to 3 min bars mostly.

 

Can you tell if this is a NEW hybrid battery and what it's manufactured date is ?
Hoping this is NOT the original hybrid battery this car came with.

 

If you just bought a new hv battery from a Toyota dealer and have these concerns, go to them. You have a full warranty for at least a year.

You can also call Toyota corporate or go to another dealer if there really is a hv battery problem the selling dealer can’t resolve.

The date code looks like 2024.

Your brake booster can and will suddenly fail leaving you without power brakes and much longer stopping distances. Both of which can cause a wreck.