I wanted to add that when I called Hyundai Motors, they said there is an extended warranty on the engine. I actually found this extended warranty in a pile of papers. How is it that this knock sensory issue cannot be permanently fixed… I don’t understand. All they have done is zeroed out the code to make it run okay for a while… until the limp mode comes back in a few weeks/months again 😡

 

Their program is what goofing your drive.. Tucson seems to be the hardest hit. Ask them to put in a new PCM, and DO NOT INSTALL THE 966 UPDATE.. Bunch of us been run around with knock sensor replace, control harness replace (they dont pay valid time to replace harness, 6hr for a harness that takes almost 11hr to install), and in the end, replace PCM and dont do update, just big waste of time

If you have the 2.0Nu,, look for cylinder scoring, but Hyundai will beat the dealer folks around about it with other rabbit hole stuff to chase, clogging catalyst backing up exhaust will drive things crazy

 

Dog Patch Steve, thank you so much for taking your time to reply!! I need to have your reply ”translated” by someone as I understand much nothing of the car jargon 😝… What did you mean by ”Hyundai will beat the dealer folks around about it with other rabbit hole stuff…”?

 

Steve member works at Hyundai so that is the correct answer. What happens - my understanding - Hyundai had that problem with engines failure. It is not your situation - it happens at much higher miles but while there be sure to replace the oil no longer than 3-4000 miles. Back to the story, when these engines start failing, they make a specific 'noise'. Hyundai decided to reprogram the car computer (called PCM or ECM or ECU for engine control module or unit, a small and very expensive computer). What this new program does is it uses a knock sensor to 'hear that sound' - these knock sensors are small sensors that 'feel' vibrations, if you want like small microphones attached to the engine side. The reprograming Hyundai did on their recall - perhaps the 966 update Steve is talking about - has the knock sensors listen for such sound of engine about to fail. When this sound happens, the computer puts the car in the limp mode. This will not save the engine, but will have the driver bring the car to Hyundai right away, before the engine would seize all of a sudden at full speed in the middle of the road which is a safety concern. By the way, limp mode means the car computer keeps the engine from accelerating past a certain speed - this is not an engine or computer fault, is just a secondary programing that starts in a specific situation. There may or may not be an actual issue. NOW this is all fine and dandy except there seems to be a problem : it seems the knock sensors get triggered even when the engine works perfectly fine. And this is perhaps what is happening with your car. It happened to mine as well. Mind you, if your search on google with "Hyundai 966 update" you will find people talking in forums that several vehicles started to go in the limp mode after the update with the engine in perfect condition. Now it may be interesting to find the reason behind this. I don't have a certain explanation, but I have two guesses. First possibility, one of the knock sensors (I think there is 2 or 3 of them) may be slightly faulty - just like a microphone that does record your voice but with a slight hiss or something. This may cause that sensor to trigger even if the engine doesn't make the sound of premature failure. The fix for this would be to remove and test each knock sensor and replace it - or replace all of them, not cheap. The second possibility is in some specific driving conditions, the engine will make a noise similar to the one of premature failure, but without for the engine actually having any issue. The knock sensor gets then triggered and puts the engine in limp mode.

Now, when you bring the car to Hyundai, be sure you are not the first with this situation, they know all too well about it - see what Steve is saying, he is working there as I understand. He is suggesting to replace the PCM. Unfortunately this is a very expensive component (perhaps over $2000) and Hyundai will most likely not do it for free. The reason for this replacement would simply be to get a car computer that doesn't have that 966 update in it. One issue may be, even if a dealership would replace the computer, they may still do the update upon installing it in the car (they can well happen to not pay attention the customer asked not to have the update done, they do this kind or errors), so you may actually go back to where you started. The other thing is, without this 966 update, if your engine will fail in the future, Hyundai will not replace it for free. Usually these failures happen past 70000 miles.

In my situation, Hyundai went and replaced one of the knock sensors at about 15000 miles and since then the car didn't go again in limp mode, now at 35000 miles. But my car is a Sonata 2015 non turbo. On internet, other Tucson owners say Hyundai replaced one or more knock sensors and their car still got in limp mode with the new sensors - so maybe the sensor(s) are not the problem or maybe they didn't replace the bad knock sensor ? I don't have the answer to this. Personally, I would try bringing the car to another dealership if possible, and insist on the knock sensors - try having replaced all of them. it's not cheap but it's the cheapest try. If you want, may even order them online - get only genuine ones - and have them replaced by an independent garage. The intake manifold needs removed for this job, I think it can be done in about 3h + parts. Again, this is just a guess, I'm not sure this is the actual problem.

Mind you, Hyundai dealers are presently very busy replacing engines, because of this they may rather be little cooperant with some other issues - which is why your dealership may have been telling you they don't see any problem, it's 'normal', etc etc. On google maps you can find reviews for the dealerships in your area, may find one that is more helpful.

As a last 'solution' if everything else fails, I would buy online a 'scanner' or 'code reader' - a more expensive one may be able to actually clear the limp mode much like Hyundai did several times when you brough in your car. Basically their 20 minute fix is they connect a scanner, clear the code and handle you back the car. It takes 2 minutes. This is not being recorded on Carfax. Now I don't know if a scanner bought online can erase the limp mode code. Better ask a technician from Hyundai if an aftermarket scanner could clear that limp code error. Maybe Steve here can tell. If this is possible, basically you will just stop the car, connect the scanner with a cable - the is a port on the lower left dash, inside the cabin - and just erase the error on the side of the road. I have myself a $150 scanner that can clear most error codes from the car computer, but again, 'maybe' that limp mode code is something more specific that only a genuine Hyundai dealership scanner can clear. I have to say that scanners purchased online are mostly made in china and quite difficult to start using them the first time. May want to find a brand that is easier to use for the first time.

Remember to change the oil regularly on these cars - be aware about quick oil change places that may or may not do this properly, and good idea to keep all oil change receipts.

I'm linking the info about the 966 update MC-10203282-0001.pdf (nhtsa.gov)

If anyone wonders about the length of this post. insomnia

 

Oragex - thank you for your reply! How would I know if this reprogramming of the car computer has been done to my car or not? Is it usually done at the factory before anyone buys it or after the owner brings it to Hyundai service with issues? Like I said, in my car’s Carfax there’s nothing (including the work the dealership did several times to bandaid the limp mode). Also, would I have to be responsible for the cost of possibly replacing the knock sensors or would Hyundai have to pay for it? If there already was a recall, wouldn’t it be Hyundai who’d have to take the responsibility to fix it so that the car is safe to drive? At the moment I cannot (I don’t want to) drive it far from home (definitely not out of state) since I don’t want to be stuck hours away from home plus the dealership I took it to yesterday told me to bring it in when it goes on the limp mode again so they can assess the situation better.
I either want the issue fixed so that whatever it is, doesn’t happen again or I want to trade in the car to something else but the problem with that is that I don’t think they’ll give me more than 12-13k for it (we paid 21-22k in late 2021) 😞

 

My '12 Veloster has been in and out of the shop over this since july'23. Still no fix.
Granted, I have 244k miles but still! Took it to a private shop and nothing. Purrs like a kitten. No knocks, misses, oil burn or anything.

 

HI. I have a question about this Knock Sensor. Last Thursday my car engine light came on and it went into limp mode. Went to Auto zone and looked up the code knock sensor- recommend replacement replace block. Towed to Hyundai and they run a diagnosis text that will test if the engine is bad. Service writer told me about how Hyundai has a life time warranty on the knock sensor. Test came back good. no engine issues.... Now they are charging me $710 to replace the Knock sensor. I don't understand why I have to pay this if there is a recall/life time warranty on the knock sensor.

Also hearing that some times the test comes back fine, then weeks later it turns out there was an issue with the engine. Fingers cross this is not my situation. I still don't understand why I have to pay $710. I'm told the recall code is campaign 953.

 

DO NOT HAND OVER CASH !

ALL 1326 MONKEY BUSINESS IS ON HYUNDAI MOTOR

 

I have to get it fixed. I opened a case with Hyundai customer service and she said it should be covered under campaign 953

 

Got last 8 of vin ? I would like to see warranty claim date for 953 install, and also see ifI can spy their data on E-Report

A --

• flashing mil & limp
• 1326
• verify ROM current version, if ROM not current, "Improved KSDS" come up available, install it
• bearing test PASS, ship it with "Improved KSDS" update

-----

B --

• flashing mil & limp
• ROM is current
• bearing test, PASS
• replace knock sensor (HMA pay them (dealer) warranty for this)

Print this for reference

 

Hey Steve, I’m having similar issues with my 2019 Hyundai Sonata. It only has 85,000 miles on it. The past three oil changes, within a month of getting the oil change, my oil lights starts flicking. When I check it, it’s usually low. Sometimes I’ve had to put oil in it. I’ve told dealership this issue but no response on what is happening to the oil. The other day, my oil light was flickering and then my malfunction indicator light came on. Car went into limp mode, towed to dealership. They are saying it’s a knock sensor and going to cost me over $700 to fix. I’ve spoke with other shops that have said they’ve had this issue several times and they said it ends up being a dealership issue because the motor needs replaced. The oil issue is causing the knock sensor to go bad and that the motor needs replaced. I’ve been told not to pay for it because they are suppose to fix it under warranty. Any advice you can advise with this issue? Your responses seem logical and very informative. Thanks!

 

You not helping matters with oil so low that the red oil light comes on

First, low oil pressure / volume does not cushion rod brgs, so we get knock that the knock sensor hears and PCM interprets as rod knock, hence flashing MIL and limp

Second, that engine is horrible for oil consume, it will foul out a plug or 2, misfire, and you show up at dealer stating engine run rough

Third, you know it using oil, get dealer to write ticket to document time, date, vin, mile, concern, and ask them to submit to Hyundai PA for oil consume testing, and see if HMA approve. Not dealer decision to make, it is HMA' game and rules

Anything 1326 is Hyundai problem, but you running low oil and 1326 as result, multiple bearing test with pass, and ROM current, Hyundai might catch wind of multiple knock sensor replace and say something

Last 8 of vin handy, let me see if you still on first version (full of bugs) or if it done 2020 or later

 

Thank you! I apologize, but this is the first time I’ve ever had to replace the knock sensor. The dealership recently done an oil change and it’s only been about a month ago, so I didn’t even know it was low on oil. I didn’t think it should be low on oil. The light came on just before the malfunction indicator light that they’re saying is the knock sensor and then it went into limp mode on me. I’ve talked to other people who have said they’ve had the same issue with it burning oil and causing the knock sensor to go bad. I never thought that it would be loosing that much oil because I have no leaks nor does it smoke or anything. Thanks for your informative input. 4802

 

You should be checking oil ideally ever refuel, you know it using oil

Get dealer to put in PA for oil consume test, let Hyundai Motor decide

Oil burn does not make a knock sensor go bad.

Oil consume is fouling catalyst

Last 8 of vin for claims history inspection ?

 

KH754802

 

Message sent 2241hr 9-12-24

 

I am experiencing the exact same thing with my son’s car! Except they said changing the timing belt, etc would fix the problem. I fell for it and spent $3500+ on repairs that had nothing to do with my car going into limp mode! I am beyond infuriated and all feels so hopeless

 

Clarify "exact same thing"

Year

Chassis

Engine

Photo of invoice reflecting job line and the parts used to make this so called repair ?

 

There is a very last resort. Trade your car in and buy something else other than a Hyundai or a Kia. I traded mine when this knock sensor junk started 3 or so years ago. Yes you will take a hit and yes you might find that the next car you buy from a different manufacturer could have a whole set of new problems, like the "wet belt" problems that Ford and a few other manufacturers are having. You need to do a lot research before you spend the silly money that vehicles cost these days. Okay I know not helpful for the current problems with Hyundais and Kias but under the circumstances I think it's the sensible way to go. I can quite see Hyundai and Kia having financial troubles if they don't sort these problems out which would be a shame because both companies (they are the same company) make nice cars.

 

Hello Steve! Same thing here - 2018 Hyundai Tuscon SEL Plus with 145k miles. Went into limp mode, hear ticking when accelerate, flashing check engine light. Was low on oil, but we did a full oil change after towing it home. Is there a way to reset the check engine and knock sensor without replacement. Is the actual knock a blown rod? I had that recall 966 I believe, does that extend my warranty? What should I do?

 

Dump it on dealer we lot for inspection

Scan, 1326, they to verify PCM ROM current, do bearing test, and go from there based on results

Do not clear codes, leave with MIL illuminated and flashing in limited power mode