Prius misfires, hesitates, dies at middle of the road-Red triangle, ((!)), VSC, Check Engine Light

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Mitko, Dec 21, 2019.

  1. Mitko

    Mitko New Member

    Dec 11, 2019
    West Palm Beach, Nantucket
    2007 Prius
    Mileage: 253,500

    Hello guys,

    I'm gonna try to provide as much details as I can so hopefully some of you might be able to help me and know the right solution.

    It was like a month ago, was driving on highway around 80mph and the car suddenly started to misfire, like on every 10 seconds it felt hard jerk. Then after few misfires the lights popped on the dash with a warning beep and the engine shut down completely leaving me with the electric motor only that drained very fast. Luckily I was on the right lane on the highway so I pulled safely on the assistant lane. Car wasn't moving at that point.

    I disconected the positive terminal from the battery for 30 seconds, put it back again and the car started and was running normally after that.

    Couple of weeks after the same thing happened. Before it shut off I noticed a clicking noise on my driver side under the lower dash. It was like a relay turning on and off rapidly in very fast time interval. (after certain period I found out there was a relay and fuse box). I pulled safely in a Walgreens parking, I scanned the codes and this is what it gave me:

    P0351 - Ignition Coil "A" Primary Control Circuit/Open
    P0352 - Ignition Coil "B" Primary Control Circuit/Open
    P0353 - Ignition Coil "C" Primary Control Circuit/Open
    P0354 - Ignition Coil "D" Primary Control Circuit/Open

    C2318 - Low Voltage Error (Power Supply Malfunciton)
    P2238 - O2 Sensor Positive Current Control Circuit Low Bank 1
    C0205 - Left Front Wheel Speed Sensor Signal Malfunction
    C1259 - HV System Regenerative Malfunction
    C1310 - Malfunction In HV System

    Might have been few more but I probably had deleted them from my saved reports.

    After that I shut the car for few minutes and started it again. There were just the red triangle and check engine light only. Engine started and was charging the battery and I drived home without any issues. I cleared the codes and car run normal for a bit but was still noticing those relay clicks around over 45mph. Then again happened and again and again. I was simply reseting the codes or the battery.

    Then I tested the Ignition coils with a multimeter, all 4 of them had resistence around 350Ohms (I don’t know on which scale on the multimeter resistence was but was reading 350Ohms).

    I tested the voltage on the connectors with the ignition on. First two were reading 12.3V and the last two showed 9.76V(not exact number but was 9V). Here was a bit suspicious so I checked the voltage on the screen (Vehicle Signal Check), and was like 9V aswell. So while car was just with ignition on and I was doing the Ignition coils testing, battery drained right away.

    After I checked the ignition coils(I replaced them few months ago), they had some carbon on the bottom which I cleaned with metal brush.

    After this tests it drove for a week I guess nicely and now started almost every time I drive it.

    Yesterday it stopped me 3 times on my way from work to home. Luckily I had where to pull and restart it. It’s not safe and so annoying. I don’t really have time to investigate and research on it because I’m working all day long. I would appreciate If someone can at least guide me what could be the possible cause so when I have time off just to know what I have to do.

    I did a little bit of research regarding the codes and could possibly be faulty ECM, bad auxillary battery, relay or fuse, bad ignition coils/ spark plugs, bad wiring…
    Hybrid battery is charging and holds charge, previous owner said was replaced recently(that was in june).

    I think that I put as many details that came in my mind at the moment, but please ask If you need any other details or checks I need to do.

    I appologize for the long text and thank you for your time :)
  2. SFO

    SFO Senior Member

    Feb 7, 2017
    Northern California
    2007 Prius
    Welcome to PriusChat!!

    Best to leave the vehicle in "Ready" mode (or off), otherwise you will drain the 12v battery quickly (as you've discovered).

    The 12v sounds suspect, have you tested it with a voltmeter or taken it to an auto parts store for testing?

    What do the old coils read in ohms, and how does that compare to the new coils at 350 ohms?

    Are you using a mini-vci cable and techstream for reading the OBD2 DTCs?

    Have the current DTCs changed since the initial scan?
    Raytheeagle likes this.