[2017SFSdwl]

This is first problem so far with 2015 Sonata Limited 2.4 with 37,000 miles. Purchased new in June 2015.
All three lights illuminated this month. Intermittent for a couple of days, continuous now. Car continues to drive fine, but Blind Side Detection not operating and I am sure the ABS and Traction Control are not functioning either.

At just over 5+ years of service, I am believing this is out of factory warranty, but have not contacted the dealer yet. I have done a bunch of forum searching and not found this problem referenced for my model year Sonata yet. Have seen a bunch of posts about Santa Fe ABS lights and hub replacement. Most posts pointed to "get the codes and diagnose".

I got an AUTEL AL619 and ran an ABS scan. Got codes C1206 01 and C1207 02, Wheel Speed Sensor Rear LH Open/Short. From the Santa Fe forum posts this is pretty much inline with what I was expecting and pleased that the scan tool seemed to point to a particular wheel speed sensor.

I raised the car, removed the wheel and began looking around. Did not see any obvious broken wires or evidence of external damage. Only looked in the wheel well as I did not have the time to follow the wire inside the vehicle.

My next step is to clean around the ABS connector at the hub, disconnect it, check that it is a clean, dry, and good connection, and test for resistance, then voltage as I rotate the wheel. What I have seen is the wheel speed sensor in the hub should have resistance and should produce an AC voltage as the wheel is being rotated. If it shows resistance and produces voltage, I would like to reconnect it, go further along the wire to the next connector and retest it there. Perhaps a continuity or ground check would be in order if I can access both end connectors.

If it does not show resistance or produce voltage, that seems to indicate the wheel speed sensor has failed and calls for hub renewal. That looks pretty straightforward. I am an experienced ship repair mechanic and automobile DIYer. From the hub change resources I have seen so far I have the tools to do the work.

I have a few questions for forum members:
1. Have you seen this before on the 2015+ Sonata? Does it sound similar to the ABS and hub renewal discussions in the Santa Fe forums?
2. Does this sound like a pretty effective diagnostic repair plan?
3. Where does the wheel speed sensor wire go after it leaves the wheel well? Is the next connector fairly accessible behind the trunk lining or below the rear seat? From illustrations I have seen of ABS Wheel Speed Sensor Wiring Harness Part Number: 59910C1000 it looks like the connector is pretty close to the wheel well pass through grommet. Where is the next one beyond that? At some control module under the hood?
4. It looks like the hub renewal is the simplest repair method, is that true?
5. Does anyone know the part number for the hub? I have electric parking brakes on the car. Looks like it might be Hyundai Part No. 52730-C1100.
6. I have assumed this would not be covered by warranty, anyone know anything different about that?
7. I bought an extended mechanical repair contract, 10 year period, Platinum level, $0 deductible at the original dealership (100 mile RT to them) at the time of purchase. The contract is called "The Mechanic" administrator is at 175 West Jackson Blvd, Chicago.
Have not pursued that avenue to get it repaired yet but considering it. Need to call them for authorization before I take the car for repair to my local dealership. Am concerned there would be some pushback or other BS over diagnostic fees or some such thing an I would end up spending more time and money fussing with those tow parties than I would if I buy the wheel hub and change it myself. Any thoughts on that? Any experience with these contract administrator people?

I know it is a lot of questions, maybe some of them belong in another forum. I'd be glad to hear your thoughts on any of this and will move a question to another recommended forum if that is the right thing to do.

Thanks in advance,
DWL

 

[xaran]

I would check with your extended warranty, it is drive line and should be covered. Since you have $ 0 deductible that should be the least expensive route
Parts cost for the hub is $200 and the speed sensor is about $ 120 so if you can get it done under warranty it is $ and time ahead.

I recall a thread about this in the LF forum (2015-2019 Sonata)

 

[Soccerguy48025]

I would check first to see if your extended repair contract would cover the costs to have your car fixed.
A few other thoughts... I have heard of wheel speed sensors going bad on Sonatas many times before, you may just need a new sensor. However, what I find unique about your problem is why did the Blind Spot Monitoring malfunction lamp also trigger? I see a connection with the BSM system requiring the correct speed inputs in order to function properly. Sounds to me like it could also be that your main wiring harness may have gone bad? This is more of a worst case scenario though.

 

[2017SFSdwl]

I would check first to see if your extended repair contract would cover the costs to have your car fixed.
A few other thoughts... I have heard of wheel speed sensors going bad on Sonatas many times before, you may just need a new sensor. However, what I find unique about your problem is why did the Blind Spot Monitoring malfunction lamp also trigger? I see a connection with the BSM system requiring the correct speed inputs in order to function properly. Sounds to me like it could also be that your main wiring harness may have gone bad? This is more of a worst case scenario though.

Yes, the multiple warning lights are a puzzle. My son told me that on the Land Rover a similar set of three warning lights was called "The Three Amigos".
With respect to a failed wheel speed sensor, yes, it may be that is the problem here, but for this model year I can't seem to find the sensor for the rear wheel as a single part that can be installed without special tools required for removal and installation. Maybe I have overlooked something.
DWL

 

[2017SFSdwl]

I would check with your extended warranty, it is drive line and should be covered. Since you have $ 0 deductible that should be the least expensive route
Parts cost for the hub is $200 and the speed sensor is about $ 120 so if you can get it done under warranty it is $ and time ahead.

I recall a thread about this in the LF forum (2015-2019 Sonata)

Agreed, if extended warranty covered this, I think I would be happy to get an authorization, take it to the local dealer and let them do the work. That would also be helpful if the problem reoccured within a period after repair.
I see the OEM hub is around $200. If my interpretation of the PN is correct, I think the sensor is part of the hub under the fixed cap with the connector on the rear.
DWL

 

[AUTOSPARK]

test for resistance, then voltage as I rotate the wheel. What I have seen is the wheel speed sensor in the hub should have resistance and should produce an AC voltage as the wheel is being rotated.

I doubt the speed sensor on a 2015 car will show resistance or produce an AC voltage when the wheel is rotated. That's 20th century technology your talking about (VRS sensors). Cars in the 21st century are fitted with active wheel speed sensors. Active sensors contain an electronic circuit and can't be tested on their own. Being electronic, they need power to make them work. So they need to be connected to the car's harness when tested.

The wiring between the ABS module and the sensor is pretty easy to test though. All you do is switch the ignition on then connect your voltmeter across the two terminals of the sensor harness connector. If both wires are good you should get approx 12V.

If I helped you fix it, why not...

Your support is greatly appreciated​

 

[2017SFSdwl]

Thanks AUTOSPARK, that is interesting information I had not discovered yet. I assumed that in the hub under that cap there was a simple magnetic sensor and a reluctor similar to what I had seen in other rotation-sensing applications. So my plan will be to clean up the area around the wire connector at the wheel hub, disconnect it, check for DC voltage. If voltage exists, assume the problem is internal to the hub.

DWL

 

[philmike]

I just had the same problem, C120601, show up on my 2016 2.4L Sonata Limited with 70,000+ miles. From what I've found online, I need to check the wiring harness to the sensor for an open or short, if that's the problem then I need part #59910C1000.

 

[2017SFSdwl]

Hi philmike, thanks for the note. I have not had a opportunity to get back to my car to check the connector as being clean and tight and checking for 12V as Autospark suggested. I hope to get to it this weekend.
I did contact my mechanical repair (MR) insurance provided (extended warranty) to open a claim and get authorization to get it repaired. The customer service rep confirmed I had coverage and told me to take it to a repair facility let them know I had an MR contract, let them diagnose the problem and have them contact the MR contractor for authorization. The MR contractor would then determine if the diagnosis revealed a covered repair. If the repair is covered- all is well financially, the MR contract covers the diagnosis fee and the repair parts and labor. If it is not covered then I need to pay for all.
I'll check the voltage first and look very closely for any "road damage" to the wiring before I go to the dealer.

 

[DIYr]

I got an AUTEL AL619 and ran an ABS scan. Got codes C1206 01 and C1207 02, Wheel Speed Sensor Rear LH Open/Short. From the Santa Fe forum posts this is pretty much inline with what I was expecting and pleased that the scan tool seemed to point to a particular wheel speed sensor.

I raised the car, removed the wheel and began looking around. Did not see any obvious broken wires or evidence of external damage. Only looked in the wheel well as I did not have the time to follow the wire inside the vehicle.

If it's possible to switch LH to RH speed sensors then see if the problem shows on the RH. That would tell you it's the sensor.

 

[2017SFSdwl]

Thanks DYIr, great suggestion and would seem to be a good way to really nail it down. With my Sonata I think the sensor is in the hub in a manner that I can't easily swap the sensor, would need to swap the hubs LH to RH.

 

[philmike]

I just had the same problem, C120601, show up on my 2016 2.4L Sonata Limited with 70,000+ miles. From what I've found online, I need to check the wiring harness to the sensor for an open or short, if that's the problem then I need part #59910C1000.

Took an ohm meter to my wiring harness. Everything checked out fine. I'm thinking I need to take my car in.

 

[2017SFSdwl]

Can you describe what you did? I am thinking you did a continuity check from each terminal position on one connector to the same terminal position on the one at the wheel hub. Where did you access the "next" connector up stream from the wheel hub?

I regret I did not get out to the car to continue diagnosis toady. I needed to get fall leaves to the curb instead- 2 days worth!
DWL

 

[philmike]

Can you describe what you did? I am thinking you did a continuity check from each terminal position on one connector to the same terminal position on the one at the wheel hub. Where did you access the "next" connector up stream from the wheel hub?

I regret I did not get out to the car to continue diagnosis toady. I needed to get fall leaves to the curb instead- 2 days worth!
DWL

Yes, I did a continuity check between each pair on either end of the cable and checked for shorts to ground. The next connector up stream is behind the back seat; behind the 4in wide section next to the door.

 

[2017SFSdwl]

Thanks philmike. We have good weather all this week, I will get the car up and check this during the week.
DWL

 

[philmike]

So I found a $60 hub with the sensor on ebay. Was able to plug it in to test it; all the warning lights disappeared. I removed the tire. loosened the rotor, removed the whole break assembly, was able to replace the wheel hub in under 3 hours with only hand tools.