Safe to drive temporarily with these DTCs?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by monfresh, Dec 2, 2024.

  1. monfresh

    monfresh Junior Member

    Joined:
    Sep 30, 2009
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    Location:
    virginia
    Vehicle:
    2010 Prius
    Model:
    IV
    Hello. I have a 2010 Prius with about 210,000 miles that started exhibiting issues.
    I called my mechanic (not Toyota dealership), and he said it should be fine to drive it to them (about 8 miles, 24 minutes, no highways). I wanted to get a second opinion from the knowledgeable folks here.

    Here's the background:

    For the first time, it displayed the "Check Hybrid System" message. My wife was driving it last week, and she said she also saw the "Check Engine" and "Power Steering" lights. She felt the car become sluggish, and she pulled over and turned the car off. After a few minutes, she turned it back on and it still displayed the same things.

    She continued to drive to pick up our kid. By the time she got back to the car, at least 10 minutes had passed, and she turned it back on, but the same things were still being displayed. So she left the car at school. The next day, I went to check out the car, and this time, the only thing that was displayed was the check engine light (not flashing). The car started fine. I didn't try driving it. I wanted to wait for the OBD II scanner to arrive. I had never used one before and just learned about them.

    When I got the scanner (Panlong), I went back to the car the next day, and plugged it in. When I started the car, this time there were no warning lights at all, and the car started fine. I tried the Dr. Prius iOS app, but it couldn't find the scanner. So then I tried the Car Scanner app, and it worked. It displayed the following codes:

    OBD-II
    P261B [0x261B]
    Engine coolant pump motor B - control circuit range/performance

    P0A0F [0x0A0F]
    Hybrid drive system - engine failed to start

    Engine Control Unit #1
    P261B
    Engine coolant pump motor B - control circuit range/performance

    Hybrid Engine System
    P0A0F
    Hybrid drive system - engine failed to start

    BCM #1/Convenience Systems
    U0101
    Data bus, transmission control module (TCM) - no communication

    U0164
    Data bus, AC control module - no communication

    U0293
    Lost communication with hybrid powertrain control module

    U1133
    Couldn't find a description for this one

    Electric Window/Passenger Door
    B2312
    not sure what this is about since the window works fine

    Electric Window/Rear Right Door
    B2312
    not sure what this is about since the window works fine

    Entry & Start/Smart Key
    B278C [0xA78C]

    U0155 [0xC155]
    Data bus, instrumentation control module - no communication

    U0293 [0xC293]
    Lost communication with hybrid powertrain control module


    Given that the car starts fine and that there aren't any warning lights currently, do you think I can drive it 8 miles to have it checked out?
     
  2. monfresh

    monfresh Junior Member

    Joined:
    Sep 30, 2009
    2
    0
    0
    Location:
    virginia
    Vehicle:
    2010 Prius
    Model:
    IV
    Update: I drove it and it was fine. No warning lights appeared.
     
  3. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
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    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    First check the engine coolant level in the plastic reservoir on the passengers side. The level should be near the seam in the tank.

    You should be able to drive slowly the 8 miles to your mechanic. Just do not drive at high speed.

    The main concern is the P261B code for the engine coolant pump. It is failing and needs to be replaced. I recommend to only use the OEM pump because it will last longer than an aftermarket pump. After the P261B code is set, if the coolant temperature reaches a certain temperature, the ECM (engine control module) will stop the engine to protect it from sever overheating. That is probably what your wife felt.

    As far as all the other trouble codes that are listed, I would clear all the codes after the pump is replaced and see which ones come back. You only need to be concerned about any "current" or "active" codes. If any of the codes are listed as historical or permanent, you can disregard them.

    Edit: Also check all the fuses in both fuse boxes to make sure none of them are blown.
     
    #3 Brian1954, Dec 2, 2024
    Last edited: Dec 2, 2024