'12 Prius - Hazard lights flashing on their own!

[@djosbun]

Excellent tip, PJ. It shows that it is worthwhile to look a little further past the standard diagrams when something just doesn't seem right.

[@VoltageDropDiagnostics]

Yes! A lesson learned for me as well!

[@ibrahimatasoy3029]

hi do you have to reprogram the car after replacing this part?

[@diydantex6150]

Thanks. My scanner was telling me to press the skid control button. Couldn't find it. Looking at the diagram i saw an input to the skid control from the Haz switch. I was looking to see if it was a double pole switch. You helped me find the correct diagram.

[@charchar8]

I have the exact issue with my 2014 FJ Cruiser. The FJ forums say it is the turn signal relay. I replaced the turn signal relay. The hazards lights are still on with engine on and engine off. I will try the skid control ECU tomorrow. Thank you for sharing the information.

[@RogueWrenching]

Thank you for this great explanation. I have a 12 Prius in the shop now and had the same issue. Unplugged the ABS module and the lights turned off. Many thanks!

[@PineHollowAutoDiagnostics]

Prius owner: I can't turn off my hazard flashers! Toyota Tech: you need a new ABS control module. Customer: damn stealership always trying to rip me off!! haha Wow! Great diag, PJ!

[@VoltageDropDiagnostics]

haha! Luckily on THIS prius, the ABS module was covered under an extended warranty up to 150,000 miles. But the other prius mentioned in the video had over 200,000 and a new one was expensive.

[@behappy0803]

Customer: I wanna fix my flasher. I don't have a problem with abs. I need to take my car to real mechanic. LOL good work PJ

[@PineHollowAutoDiagnostics]

@@VoltageDropDiagnostics Can you just snip the hazard wire going to the ABS module?

[@VoltageDropDiagnostics]

@@PineHollowAutoDiagnostics yeah. I know a couple of techs that have without creating any issues. But I’m gonna be honest, i can’t find out why that circuit is ran to that module. I don’t know if during emergency braking, it causes the hazard lights to come on? I honestly don’t know what it is there for.

[@PineHollowAutoDiagnostics]

@@VoltageDropDiagnostics Only one way to find out! :D

[@PeterCastle2A]

Thanks for the help PJ! I was able to get the lights to go out by pulling fuse 7.5A ABS Main #2 fuse, thanks for pointing me in the right direction!

[@VoltageDropDiagnostics]

Nice! Glad that I could help!

[@adamhonda98]

Yo this is the same thing that happens in mine as well but what did you replace to fix it was it the ABS module? Because he mentioned flasher unit as well in the video

[@VoltageDropDiagnostics]

@@adamhonda98 yeah. The abs module fixed it.

[@adamhonda98]

@@VoltageDropDiagnostics awesome I'm gonna throw one in since I've done voltage and continuity testing and and everything else is fine

[@mmctaggart3012]

My 2012 has suddenly developed this problem, I may forward this to my mechanic! Thank you so much for sharing this info you really thought it out very clearly.

[@VoltageDropDiagnostics]

Glad it helped

[@bornforparadise7517]

Great video brother , very interesting , iam a Toyota tech too and this is the first time that i see this ! Thnks for sharing , in my country i would directly cut the wire going into that circuit , cuz no one here is going to get a new abs unit for a hazard light always flashing , even removing the hazard fuse and never using them again would be a better solution here .. keep up the good work bro

[@VoltageDropDiagnostics]

Hey, what country are you from? I’m interested to know.

[@bornforparadise7517]

@@VoltageDropDiagnostics Lol im from mauritania in West Africa , i just replied to one of your videos asking about something that i found during work , where can i contact you , if we can stay in touch !

[@techwrightauto]

Thanks for the video. Saved me a ton of time diagnosing a 2010 that just came in my shop. I ended up just cutting and taping off the blue wire that goes into the ABS module for the hazard light input and now the car is fixed and hazards work normally. I'm not really sure under what circumstances the brake controller would need to know if the hazards are on. Its not worth thousands to repair though.

[@thetahedgecapital1008]

Did you cut the wire from under the dash? Or at the connector?

[@techwrightauto]

@@thetahedgecapital1008 right by the connector under the hood. I tried to leave enough on the connector to splice back if needed. But there have been no issues.

[@thetahedgecapital1008]

@@techwrightauto Thanks for the swift reply... We are back rolling... Thanks for your help

[@lyndonthan4350]

I've done that as well. Cut the light blue wire at the ABS/Skid control plug. This stopped the hazards from flashing, but I still have a parasitic draw on the system of some 8 amps. So at first it seemed like it solved the problem, but later on I found the car dead again...Having a hard time finding the parasitic load. I've pulled a lot of fuses but the load remains. ABS Main #2 fuse didn't resolve anything either.

[@pensador72]

Thank you for all your insight! My connector has 3 blue wires. How do I know which one to cut?

[@marklennon1]

Had a guy on FB recommended your channel to me because I got a new maxisys ultra. Love your videos brother!

[@VoltageDropDiagnostics]

Awesome! Thank you!

[@atwoodracing20]

Just got the same car with same problem in the shop, thanks for the video, going to check it out on Monday

[@VoltageDropDiagnostics]

Nice!

[@YYZFLIX]

Great Video, Thanks for the tip. Today was snowy and slippery after a little the hazards came up and stayed up.

[@wyattoneable]

Good catch on the differences in the wiring diagrams. Like Ivan said "Great diag".

[@VoltageDropDiagnostics]

Thanks Wyatt!

[@billyyoder8171]

Thank you PJ. Good job again. Have a blessed and safe week to you and your family.

[@VoltageDropDiagnostics]

Same to you

[@kuniboy1]

great video man! cant we just cut the wire going to the skid control ecu?

[@timlavender741]

Great video! What is the part number of the Skid Control Ecu that you replaced?

[@GreaseMonkChronicles]

Would Toyota cover this under warranty, being that it’s a internal short in the actuator? mines a 2010 Prius too

[@millersoldmitsubishis]

Hey PJ, I am working on a 2011 prius with the same issue. I can't get that schematic, so, what's the fix?

[@SuperMarioDiagnostics]

Ouch, sucks to not see that in the diagram. At least they should put some dotted lines around that connector to show its incomplete. Thanks for sharing dude, very nice find! I'm going to go look at this diagram as well (Just saw the second diagram, still going to look at the diagrams available to me)

[@VoltageDropDiagnostics]

I seen that alldata had a redrawn diagram that also didn't show the skid control circuit. But i did see that alldata had the overall diagram just like toyota SI.

[@robertonava5564]

hello thank you very much for your video because it helped me to identify the fault. Please can you tell me what color is the cable that can be cut in the connector of the ABS module. Thank you

[@VoltageDropDiagnostics]

Off the top of my head, i don’t know. Sorry.

[@magid5441]

Thanks for sharing your experience.. You very smart man

[@VoltageDropDiagnostics]

Im just a normal tech trying to share the little knowledge that I have lol. Im not smart, I learn from smart people!

[@semirm8248]

I have a similar issue with hazerd lights stuck on but they start to blink faster and faster as the car starts moving? Anything input on that?

[@rainafortini5797]

Happy new year and while you’re enjoying the long weekend I can’t bring my car in so thought you might be able to give me some peace of mind, or not please be honest… Last night my check engine light came on out of the blue along with the hybrid system warning light - as I was driving I could feel the engine ever so slightly hesitate, so I immediately turned around to go home because it was very very late didn’t want to break down somewhere. Sure enough 25 yards from my parking spot the car stalled hummer engine stopped and I think there was some dinging. I am mediately turned off the car I don’t remember why, maybe it told me to? But then I started it back up and was able to at least drive to my parking spot and left it for the night. The next morning I turned it on same two lights were on, check engine and HSSW… so I turned it back off. Opened up my owners manual to see what it meant couldn’t differentiate between the thermostat and the HSW so I quickly turn the car back on to compare and the check engine light along with it we’re both gone they didn’t come back on. Does this sound like it might be erroneously alerting? I wonder because two weeks ago a red light in the middle of the dash for airbags came on, I ignored it end it too just went away the next day it may have been two days but very quickly it was gone and I completely forgot about it until last night That didn’t have the check engine light with it of course but other than that it seemed like a similar false alert? Do you know I so want that to be what it is as I’m worried about my batteries are some expensive fix but then of course the electrical system can be just as expensive I guess so any unofficial tips or advice you could give as I pull my hair out of my head for the next three days? Thank you very much

[@ohtro]

Pat, my prius is a 2010. Is there a difference in the location of the ECU. Also, after you changed the Skid control ECU do you need to bleed the brakes? It would be nice to see or hear how the process works after you unplugged the ECU in the current video. Thank you for solving this nightmare.

[@VoltageDropDiagnostics]

Yeah, the brakes will need bled. And they’ll need bled with a scan tool.

[@ohtro]

@@VoltageDropDiagnostics Is the ECU for the 2010 the same process and located in the same location as the 2012? All you did was replace the ECU and bleed the brakes and it was fixed?

[@VoltageDropDiagnostics]

@@ohtro I’m not 100% sure if they’re in the same location. You might want to look in service information and verify it’s location

[@ohtro]

Pat which dealership do you work at? Would love to bring my car to you. I am afraid if I take my car to my local Toyota dealer they wont get it right.

[@frankarlocuevas4940]

Hi PJ, fellow MDT from NJ here! I have replaced two of these already for this same concern. Not super common but they do pop up every now and then. Excellent video explaining how the hazards and skid control ECU are integrated.

[@VoltageDropDiagnostics]

Thanks! What part of NJ are you in?

[@frankarlocuevas4940]

@@VoltageDropDiagnostics North Jersey. Toyota of Hackensack. I'm a shop foreman there.

[@asa88asa88]

Hi, thank you for the video. May I ask if you replaced the abs actuator? to fix the issue or just replaced skid control ecu? thank you again for the helpful video.

[@billrimmer5596]

Wow!! Excellent find!! I’m just thinking if a problem like that came to me. What would or could I do? Hope that PJ would take pity on me.

[@VoltageDropDiagnostics]

Luckily I searched in alldata and all of the information was provided in there as well. Just had to dig deep enough.

[@EliTheOBDTech]

Thanks for the quick tip PJ.

[@VoltageDropDiagnostics]

You bet!

[@hamham4547]

Nice job thank you for sharing this with us, why the skid controle module need the hazard signal?

[@VoltageDropDiagnostics]

Thats a question that I dont know the answer to.

[@NurulIslam-bn2rm]

If possible can you please do a video to isolate the hazard signal from the skid control module.

[@iLeaveYouOne-]

thank you, my team leader sent me on a goose chase and I looked this video up and helped a lot

[@tomplant949]

But how did you fix it?

[@VoltageDropDiagnostics]

Magic!

[@kami009]

Don’t bullshit us with the video if your not going to get us a solution

[@paulww2270]

Is replacing this switch enough I have the same problem. Everything worked great in my car .I repair my car myself. Even the engine itself was replaced this year. In addition, I checked my Toyota prius 2010 battery myself today. It is in very good condition. I have a problem because the car only makes 36 miles. And recently it dropped to 30 m / g. The lights turned on by themselves and I am not able to turn them off until the battery is discharged. What should I mention, what part to get rid of this problem. Everything works great for me. Only the lights are flashing. Sorry for the language. I'm writing from Poland

[@FruitTreeAddict]

Same thing happening to my 05 right now! I just had the ABS brake system replaced 3 years ago

[@J.T672]

Great video , we had a Toyota auris with exact same fault . New abs ECU with actuator was needed making it very expensive. Just quick question regarding input,output signal from abs ECU ,would this make hazards warning lights flash in emergency stop ? also would it be safe to remove this wire from abs ecu ? I've not seen any bulletins (tsb)for this fault ,even though it's more common than you think .

[@VoltageDropDiagnostics]

That question is one that I dont have an answer for! You might be right about the hazards light coming on during emergency stops! Ill need to dig into one and see why.

[@grabovg]

Great video PJ ! I get stumped on junction connectors sometimes too. I’ll have to check out overall diagrams more

[@VoltageDropDiagnostics]

Yeah, lesson learned for me!

[@TIMI2011]

great video! just got the same issue today with my 2012 Prius :(

[@TIMI2011]

I unplugged skid control icu and flushing stopped like yours. Can you share how did you fixed icu issue?

[@VoltageDropDiagnostics]

I replaced it on this one.

[@NurulIslam-bn2rm]

Great video PJ. Do you have a garage where you can fix these issue please?

[@VoltageDropDiagnostics]

No, I dont have my own garage. I work in a dealership.

[@shawnydAB]

So is it tve skid control module or broken/ frayed wires from junction plug creating a short to skid control?? Please help!

[@abdulkhaliq3485]

My car have got the same problem please can you tell me what the part call please?

[@prophetseven728]

Hazard Lights will just start blinking and will not shut off on FJ Cruiser. Had to unplug the Fuse. But there went the turn signals. How do I get these Diagrams for the FJ? Never done anything like this before. Thanks

[@randyvandyke1]

What I got from this was that the skid control ecu needs to be replaced. What you said in a comment was that you replaced the flasher relay. And then bled the breaks with a scan tool. Did I get that right? Thanks so much.

[@VoltageDropDiagnostics]

Skid control ecu needed replaced

[@randyvandyke1]

@@VoltageDropDiagnostics thank you so much for the quick reply.

[@pl5882]

Is that because in the event of a crash the hazards come on? Also do you (or intend to) post your vids on other platforms like Odysee or Bitchute? Thanks!

[@VoltageDropDiagnostics]

No, this vehicle wasn't in an accident. At least as far as I am aware. I haven't heard about odysee or bitchute. This is the first that I am hearing about them! I will look into them.

[@danlarkin2181]

He means if the vehicle crashes the hazards auto come on as a warning to other drivers.

[@VoltageDropDiagnostics]

@@danlarkin2181 i wonder why it wouldn’t head to the airbag module for that. But it makes sense

[@IvanS785]

What was the issue causing the hazards to stay on? Whats the name of the part that goes bad and is it purchasable/fixable?

[@VoltageDropDiagnostics]

I didn’t mention it in the video?

[@lesrushworth4116]

Same problem here at Toyota dealership, this ones a 2015 but no skid control?

[@adamhonda98]

Weird I pulled ABS main fuse one and the lights flashed when I moved but when I turned the car off the flashers turned off this time what does that even mean?

[@adamhonda98]

I replaced the flasher relay and it fixed the problem

[@mikeshaban1242]

Hi Do you know where is the same plague in Prius 2010 Thanks

[@DIYDaveOK]

Man it's a little gotta be a little frustrating to realize you can't always trust OEM diagrams! Good job as always, PJ, and thanks for the video!

[@VoltageDropDiagnostics]

Yeah, I guess technically I was able to trust the diagram. I just wish the nice interactive diagram showed the entire picture.

[@randyvandyke1]

Hey, my mechanic called a dealership and they seemed to say that plugging in a new skid control ecu was just the beginning. Is it as simple as plug and play or is it more complicated? Scanning or coding or resetting?

[@randyvandyke1]

Thanks in advance.

[@IAMNOSLEEP]

Thanks for sharing PJ... Cheers.

[@VoltageDropDiagnostics]

You bet

[@hxc7273]

Would be cool to see a video of you programming the new module, if it's required. Did you have to bleed the brakes too or were you able to just replace the electronic portion?

[@VoltageDropDiagnostics]

No real "programming" needed. And it would need to have the brakes bled. And thats a pain. Usually takes about 30-45 minutes to bleed these systems after replacing those.

[@anthonyocchuizzo9109]

I am having the same problem on my 2010 but it looks different under the hood than the 2012 any suggestions..

[@VoltageDropDiagnostics]

It’s going to be about the same between 2010 and 2012

[@techwrightauto]

You probably need to take off the wipers and cowling to see the ABS module and plug that are in the video.

[@romanosautomotive]

Great video PJ. Clearly explained!

[@VoltageDropDiagnostics]

Much appreciated!

[@drewbush6535]

Do you like the Mitchell software

[@VoltageDropDiagnostics]

Honestly, I haven't used mitchell in years.

[@E-bike-sonic]

Keep them videos coming!!

[@VoltageDropDiagnostics]

Will do!

[@arthurfricchione8119]

Great video. Guess you have to have access to numerous diagrams. Would you recommend if available going to an overall diagram first and then going to a specific wiring diagram? Thanks for the heads up stay well and safe Artie. 😊

[@VoltageDropDiagnostics]

After this vehicle, I think that I am going to first look at the overall diagrams first from here on out. I probably spent 45 minutes or more researching that circuit before running into the overall diagram that had more info.

[@gregjones8501]

Thanks for the knowledge brother!

[@VoltageDropDiagnostics]

Any time!

[@mridware9694]

I have one question How can I connect my horn to flasher signal because when i lock door the flasher flash but no horn is connected to flasher circuit in Rav4

[@VoltageDropDiagnostics]

Happen to notice if one of the doors don’t actually lock? The horn won’t sound unless the door latches send a signal that the doors actually locked. OR there is a customizable feature that turns off the horn with door locks.

[@mridware9694]

@@VoltageDropDiagnostics it is without horn sound from the factory but i want to connect horn with the hazard signal so whenever i lock it make peep sound like Altima

[@behappy0803]

@@mridware9694 He just gave you an answer above. there is customizable feature so horn make sound when locking and unlocking doors

[@mridware9694]

@@behappy0803 how we can use that feature in 2013 Rav4

[@myins6140]

My parents are giving me their 2011 Chevy HHR and one of its problems is the four ways just come on in the middle of the night and kills the battery

[@tylerlong4696]

Any other reasons why they would just randomly come on?

[@exmotorsports]

Wow.. Like you said "This wire diagram is completely incomplete.!" Lol That sucks bro, They could have at least thrown some dots around that connector so you would know there's more to that connector. Wonder how this would look from another service diagram.? Hmm...I might have to look at that. Great work bud. Now every time I see a Prius with it's hazards on, I'm gonna think of you and that dang Skid ECU. 🤣🤣 Cheers Brother and thanks for sharing.

[@VoltageDropDiagnostics]

"completely incomplete" hahaha I was going to say "completely wrong" but mid sentence I realized that it wasnt an accurate statement hahaha

[@exmotorsports]

@@VoltageDropDiagnostics Lol... Its all good. Dam near made sense really. 😂 Keep up the great work you do. Appreciate the videos bro. Cheers

[@E-bike-sonic]

Great find!!

[@VoltageDropDiagnostics]

Thanks!

[@joeluang8695]

Could a bad ground wire have caused this issue?

[@VoltageDropDiagnostics]

It’s possible, but unlikely

[@johnbennett7247]

Thanks brother!

[@VoltageDropDiagnostics]

Thank you!

[@shawnalrj3887]

This was so helpful..thank you

[@danielmerritt4031]

thank u for posting. great diag

[@VoltageDropDiagnostics]

No problem!

[@two6s722]

Those zany turd gen prii... Nice work, as always, PJ.

[@VoltageDropDiagnostics]

Thanks!

[@Usmanthemecano]

Q. I have a 2016 Camry 2.5l and car stalls randomly with codes p0015 p0017. I have diagnosed it on my channel. I decided to replace the timing chain tensioner and oil change. While it ran fine initially it stalled on me as I was pulling in. I heard what sounded like a timing chain rattle or valve train noise and then engine stopped. Turned ignition off and on again and it ran fine. Briefly a message (low oil pressure came on)... I revved it very hard and ended up with a p0016, p300, p0302, p0303, p0304. In your expertise is this a common occurrence? I have experienced similar issues with the 2.5l engines. Is there a TSB about it? What are the common fixes? Thanks bro

[@PineHollowAutoDiagnostics]

hmm very strange. Has it been maintained properly with synthetic oil changes? Definitely sounds like a timing problem.

[@Usmanthemecano]

@@PineHollowAutoDiagnostics it's a salvage vehicle with less than 50k miles. I did replace the oil with toyota 00-20w. I do not have the vehicle maintenance history. I did a capture of cam and crank. When compared to a known good it was identical. But that was before the tensioner change and p0016. So I'm planning to do another capture to see whether it's still in time. The owner states that it's running fine though the CEL is on.

[@abduahmed9685]

I have Toyota perius 2012plus model then a year ago come same issue and today I got same problem when turn of car still hazard on even if turn of the car. Same problem what is solution.

[@danlarkin2181]

It would be a output to the hazards not an input from the switch.. guess that’s not why they are linked

[@VoltageDropDiagnostics]

Know why the ABS module turns on the hazard lights?

[@allendib4855]

I have a 2010 vw passat and once i had to stop real hard and noticed that the hazard lights came on automatically. It doesnt do that every time the abs activates... only during hard decceleration. So maybe it will ground the circuit if it detects hard decceleration to warn other cars

[@VoltageDropDiagnostics]

@@allendib4855 I’ll need to try that!

[@mikeshaban1242]

Hi Can you send me the location for the same plague in 2010

[@catface5462]

I’m having the same symptom with my 2013 Chevy equinox

[@VoltageDropDiagnostics]

I wonder what is wrong with it.

[@japhiesibs9271]

Need help hazards lights not switching off on Toyota Alphard 2003 model

[@el_mcnuggy]

Is there a fix?

[@erosmyers]

You didn't tell consumer view to fix it. I just had my turn signal flash on immediately turn off while just standing near car . why

[@darrylpalma8784]

I ran into this one. The flashers would flash faster when driving!

[@VoltageDropDiagnostics]

I heard about that from a couple other techs! They also mentioned that there was a rear speed sensor code as well.

[@ohtro]

Darryl, did you find a fix for the turn signals speeding up when driving? Will replacing the skid control ECU work for that issue as well? Also do you know where the Skid Control ECU is located in a 2010 prius?

[@darrylpalma8784]

@@ohtro I had the same problem with the hazard lights flashing on their own and it would also flash faster when I drove it. The skid control fixed it. It’s under the cowl. I believe it’s all one assembly with the master cylinder and brake booster if I remember correctly. I also think it might have had an updated part number for another known issue. I had mine a couple years ago.

[@ohtro]

@@darrylpalma8784 what was the year of your prius? I have a 2010 and in the video it was a 2012. I just wondered if the skid controlwas in same place.

[@darrylpalma8784]

@@ohtro I don’t remember what year I had but I’m pretty sure in a 2010 it’s in the same place. You won’t be able to see it until the cowl is out of the way.

[@benmoretti5242]

HOOOOOOOW TO FIXXXXXXXX?????????

[@kimanimccoy472]

Yoh shit ain’t quick …. Stop posting