OBDII codes Cruise control/brake switch A - circuit malfunction & Engine control module (ECM)

Discussion in 'Gen 2 Prius Technical Discussion' started by Kristen678, Aug 6, 2020.

  1. Kristen678

    Kristen678 New Member

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    I am occasionally getting a combination of warning lights on my dash: Parking brake, Traction Control, and ABS. This started right after I got an oil change in which they apparently tried very hard to reset the Tire Pressure Sensor which is on because one of the tire sensors is bad. It didn't start until I'd driven for an hour and 45 minutes...when I restarted the car a few times after the long drive, it popped on. The next day, it popped on after another hour and 45 minutes or so. It now randomly comes on after shorter distances. When it does, there's a quick shift in the car like the brake activating - once the lights are on, I can't tell anything has changed. The cruise control acted up once before this started happening (not sure it was on the same drive but probably was)...the light was blinking and the cruise control didn't work until I turned the car off and on again.

    I bought a code reader and received these errors:

    P0571
    Raw code: 0571
    ECU: 7EA
    Status: Confirmed
    OBDII: Cruise control/brake switch A - circuit malfunction
    Toyota: Cruise Control/Brake Switch A Circuit Malfunction
    ============2==============
    P0607
    Raw code: 0607
    ECU: 7EA
    Status: Confirmed
    OBDII: Engine control module (ECM) - performance problem
    Toyota: Control Module Performance
    ============3==============
    P0571
    Raw code: 0571
    ECU: Hybrid engine system
    Status: Confirmed
    OBDII: Cruise control/brake switch A - circuit malfunction
    Toyota: Cruise Control/Brake Switch A Circuit Malfunction
    ============4==============
    P0607
    Raw code: 0607
    ECU: Hybrid engine system
    Status: Confirmed
    OBDII: Engine control module (ECM) - performance problem
    Toyota: Control Module Performance

    I used the device to clear the code but it came back on more quickly after that.

    I called my regular hybrid mechanic but they are backed up for a month. I'm hoping some clever folks on here could help me. Is the problem related to the attempts to reset the tire pressure sensor? Is the car unsafe to drive? Is the repair going to cost me an insane amount? I'm stuck on the next steps and would be very grateful to anyone that can offer suggestions.

    Thanks in advance!
     
  2. SFO

    SFO Senior Member

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  3. Kristen678

    Kristen678 New Member

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    Thanks for the welcome and the response.

    It has about 188K miles, but both batteries have been replaced in the last two years.

    As for the device, it is a Veepeak OBDCheck BLE OBD2 (
    ) and the app used was Car Scanner ELM OBD2.

    Thanks also for the links. I checked them out and am confused as to why these errors would present at the same time. Any idea? Also, the errors happen when the cruise control is not on. o_O
     
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  4. SFO

    SFO Senior Member

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    Never heard of that app before, it may not be fully compatible with toyota hybrids, some members here use Dr Prius app or the Torque app.

    The best in class for reading OBD2 codes (DTCs) would be a mini-vci cable and a copy of techstream (toyota technician software).
     
  5. Kristen678

    Kristen678 New Member

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    Thanks, I'll try another app the next time the code pops to see if there's additional info.

    Does anyone have a suggestion as to why those two codes would come up together?
     
  6. bisco

    bisco cookie crumbler

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    they may not with the tech stream
     
  7. Kristen678

    Kristen678 New Member

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    Thanks for your suggestions!
    I tried a few things and finally have more info. First, I downloaded Torque Lite and Dr. Prius but neither were helpful. Garage Pro pulled a single code: C1249, Open in Stop Light Switch Circuit. I tried getting to the switch but couldn't remove the lower panel. I realize there might be other problems and not the switch..I saw something about the speed sensor being a potential option. Since the warning lights don't come on often, I was in a holding pattern but this morning they went off and I was able to verify that the brake lights aren't staying on. When I hit the brake, only the brake light in the hatchback activates - the others don't come on. When I remove my foot from the brake, it goes back off. I restarted the car to remove the warning lights and repeated the process and found that the problem is always happening. I think this eliminates a few of the other options and brings me back to the brake light switch but I haven't seen anything about it failing in this way...I've only read about it causing the lights to always be on. Can anyone confirm?
     
  8. dolj

    dolj Senior Member

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    Hi Kristen, I'm not sure about "the sensor" being a problem and is likely a red herring as it is not mentioned anywhere in the inspection procedure for the code C1249. Here is more detail on this actual code:

    DESCRIPTION

    The skid control ECU inputs the stoplight switch signal and detects the braking condition. The skid control ECU has a circuit for open detection inside. The skid control ECU outputs the DTC if it detects an open in the stoplight signal input line when the stoplight switch is off, or an open in the stoplight circuit (GND side).

    DTC No. INF Code Blink Code DTC Detection Condition Trouble Area
    1 C1249 49 520 Stop light switch circuit is open for at least 10 sec. when IG1 terminal voltage is between 9.5 V and 17.02 V
    • Stop light switch
    • Stop light switch circuit
    • Stop light bulb


    The full inspection procedure is linked below which will take you through the logical diagnostic steps. Please note that if the "bulb" is blown as mentioned in the inspection procedure, it refers to the LED cluster, which is not a serviceable part. Before deciding if the bulb is blown, check that the stoplight plug is clicked securely in place. If it is blown the whole "Lens, Rear Combination Lamp" needs to be replaced. If you were up for opening the lens unit and unsoldering each LED and soldering in new LEDs then there are maybe two threads here detailing that process. The guy did say, if he had to do it again, he would just buy replacement lens units. You could also try junkyards/pick-n-pull yards for replacements, too.

    Part numbers:
    • LENS, REAR COMBINATION LAMP, RH - 81551-47100
    • LENS, REAR COMBINATION LAMP, LH - 81561-47100
    Note: 2004-2005 Gen 2s use a different part for these lenses so ensure the correct model year are procured.

    Inspection Procedure | DTC C1249/49 | Open in Stop Light Switch Circuit

    I hope that is of some help.
     
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  9. Kristen678

    Kristen678 New Member

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    Thank you dolj - that's very helpful!!
     
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