Gen 2 won't shift from Park to Drive or Reverse with C1256?

The C1256 has two sub-codes (INF codes) – 141 and 143.

The conditions to set with the 141 INF code are:

When either condition below is met:

• Braking operation is input when the accumulator pressure is less than 12.45 MPa and the vehicle speed is input (the detected value changes if the accumulator pressure is low after system start).
• Accumulator pressure is less than 14.62 MPa for 120 seconds (changes according to power source voltage) after system start (it stores the DTC after the conditions are met, and drives the buzzer).

The conditions to set with the 143 INF code are:

When one of the following conditions is met:

• Any of the wheel cylinder pressure sensor values are lower than the target value for at least 0.5 seconds when the accumulator pressure is less than 14.62 MPa and the vehicle speed is input.
• Accumulator pressure changes little when the accumulator pressure is less than 14.62 MPa for at least 1 sec. without braking (and the pump motor is operating).
• Accumulator pressure is less than 14.62 MPa for at least 0.5 seconds when the motor relay is malfunctioning.

If you can get the INF code, it would help you to focus on the correct area.

Regardless of the INF code, the trouble area is the brake actuator assembly (accumulator pressure, accumulator pressure sensor, pump motor).

The most likely reason is that it is not safe to drive the car in this condition.

This code has nothing to do with the reconditioned instrument cluster electronics.

I'm not sure why you seem to find it hard to believe you can have more than one fault at a time, but there you go.

 

I also find that kind of hard to believe I think something else might be going on as far as I know when my accumulator and break actuator were failing so badly that applying the brakes would cause one of the front calipers the honk and one of the rear wheel drums wasn't even grabbing properly the car would turn sideways almost breaking it was like one caliper and one drum were working I drove this car like this for about a week seriously the gold car my work vehicle and I still have it replace the actuator and the braking became normal with the car always started and ran even when I drove to 45 miles with a near dead hybrid battery engine running and fan on all the time to pick up a new one no problem starting and driving I don't think it's just my vehicle. If you take that cheat code scanner and you clear the codes and then immediately after that you clear the codes again even there if there aren't any now push the start button did the car just start and ready if so that indicates another problem

 

Our 2007 prius sounded like it was/is having similar issues as op, locked in neutral, triangle of doom lit, and non-drivable. Had it towed.
It's at the Toyota dealer now. They did a $150.00 scan (I do not know which codes were actually drawn. I'll get them tomorrow). Service "tech" stated that the issue was in the main drive battery (IMA in Honda terms) and/or control computer. They listed that further testing would need to be done ($1200.00). If it was the battery or control, that will cost $3500,00 each ($7K total) before labor....
We went car shopping today, defeated.
This is my first post here I believe. I am asking if there are any suggestions for remedy or should we let this car go?
Thanks

 

Sounds like you may have the hybrid isolation fault get it away from the dealer get ap200 for 68 bux . And get to troubleshooting on your own that save cash at up front . Get back w real codes that you're reading .

 

You should get some help after you report the codes that the dealer found.

 

OK... I got the 2 Codes
-P0AA6 battery (?) and
-P1256 accumulator fault

 

Codes:
-P0AA6
-P1256
Heavy rain here recently (as OP). I do have Code reader but don't know how to read Prius with Push Start. What is an "AP200 at $68"?

 

Did you mean C1256? There is no P1256 DTC on a Gen 2 Prius.

If it is C1256. There are three flavors of the code:

• C1256/56 (accumulator low voltage malfunction) may be memorized if the power source voltage drops. This is mentioned in the diagnostic for C1241/41 and C1242/42.
• C1256/57 sub-code 141. This code is detected when either one of the conditions below is met:
  • The braking operation is input when the accumulator pressure is less than 12.45 MPa and the vehicle speed is input (the detected value changes if the accumulator pressure is low after system start).
  • Accumulator pressure is less than 14.62 MPa for 120 seconds (changes according to power source voltage) after system start (stores the DTC after the conditions are met, and drives the buzzer).
• C1256/57 sub-code 143. This code is detected when one of the following conditions is met:
  • Any of the wheel cylinder pressure sensor values are lower than the target value for at least 0.5 seconds when the accumulator pressure is less than 14.62 MPa and the vehicle speed is input.
  • Accumulator pressure changes little when the accumulator pressure is less than 14.62 MPa for at least 1 second without braking (the pump motor is operating).
  • Accumulator pressure is less than 14.62 MPa for at least 0.5 seconds when the motor relay is malfunctioning.

The P0AA6 has one sub-code – 526 – that means an electrical isolation fault was detected, but I need one more power cycle to determine which HV sub-system has the fault. On the second power cycle, the specific area is indicated by one of four sub-codes (INF codes) – 611, 612, 613, and 614. The specific areas are shown in the diagram below:



If the Toyota technician pulled the 612 INF code, then yes, it would be your battery. If it were one of the other INF codes, then no, it is not your battery.

 

Usually open HV case see the issues very quickly. Or spend a lot of time looking around at all the other things and then you'll get back to that that. The orange wires going from the battery to the inverter are rare unless you drive like mad Max in your car looks accordingly. The AC can be just unplug for testing .

 

It is an Autel AP200 scanner that can read all the trouble codes in your Prius. Instead of taking the car to the Toyota dealership for a $150 scan, you use the Autel AP200 to read the trouble codes yourself. Take a look at this thread,
https://priuschat.com/index.php?posts/3248209

You can buy the Autel AP200 on Amazon for $70.

 

Or read the INF code and spend your time looking where the problem is.

 

Usually unfortunately that's where it is going. By posts here and round the world last 28 or so . The AC and cabeling is generally outlier unless . At least seems so . And if it's a new to me car I can see the other two quickly . And I need be looking in battery anyway past time n all.

 

That's especially where it's going if the code is 612....

 

Thanks everyone for your replies.
I am overwhelmed with this newer complexity in trying to have further knowledge of technical applications for my wife's Prius. She bought her first, brand new off the lot in 2005. Squirls destroyed it (ate the electronics) and insurance company helped in replacement (our second Prius II) around 2012. This is the car I am hoping to save this car from being towed to the junkyard. It's a pea green "green" machine as tombukt2's above.
I already have a scanner (Can OBDII U581) that I have used with my 2001 Honda Insight but did not know how to use it with the Prius. Keeping the car in prestart with key is not possible with Prius. I don't know how to use scanner with key-less start so I was not able to read codes myself.
The Prius is still at Toyota dealer. I am tempted to let them do the work replacing antilock actuator brake pump. I can get one Toyota new for about $1200.00 (toyotapartsdeal.com). It looks like it takes about 1 hour to complete (Toyota charges $185 per/hr). With having them clean and replace brake fluid, I am looking (hoping) for maybe circumventing the P0AA6 code (battery)?
This would be about a $1500.00 gamble, contrary to their (Toyota dealers) $8200.00 plus suggestion for cure.
Am I being unrealistic? We are in process to purchase a used Honda Accord for my wife to use while we sort directions for this Prius. Dealer there volunteered that he would use his flat bed and bring our Prius to his lot for parts or repair. We just got brand new tires (4) for this.
We also could have Prius towed to my yard, but I feel limited in automobile technical abilities as listed.
That's where I am at this point. I'll contact Toyota Dealer later today with budding game plan. They could hold car there, but may start changing daily fee.
I feel that I have time. We have really enjoyed our Prius ownership and would be sad to let it go.
Any and all further feedback and suggestions will be greatly appreciated!
Thank you
Tomg

 

That's something you pretty much need to know how to do. IG ON without starting is: two presses of the power button while your foot is OFF the brake.

 

thanks for the info

 

Our green "green" machine was picked up this afternoon and hauled away. Sad day but moving forward.
Good luck keeping these on the road. Thanks for the support and feedback.