Code C1237, stability and hill descent controls lightning?

2018 HYUNDAI TUCSON
50,000 MILES • 4WD • AUTOMATIC
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DAN ONDO
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Hello all,

There is the stability control and hill descent control signals permanently lightning on my dashboard and I got this error code on my vehicle listed above TL when launching a diagnostic C1237.

Can you help me to determine the problem?
Aug 4, 2023 at 11:18 AM
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JACOBANDNICKOLAS
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Hi,

Before I confirm my thoughts, I need to know which engine the vehicle has. There are three different ones that were available. See pic 1 below and let me know which you have.

Now, the code, in general, deals with the ABS control module (HECU, hydraulic electronic control unit). This code may be specific to the pressure sensor which is integral to the module. If that is the case, the HECU will need to be replaced.

Please confirm the engine size for me.

Take care,

Joe

See pic below.
Aug 4, 2023 at 9:39 PM
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DAN ONDO
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Hello Sir,

First of all, thank you for taking time to reply. This is so really appreciated.
My Tucson's engine is D 2.0 TCI-R so it should be L4-2.0L in your list.

Regards,

Dan
Aug 5, 2023 at 1:42 AM
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STRAILER
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Can you please double check the code number? Code C123702 does not exist in the standard OBD-II (On-Board Diagnostics) code list.
Aug 5, 2023 at 10:40 AM
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DAN ONDO
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Hello Ken,

Please have a look at the diagnostic obtained below.


Thanks
Aug 5, 2023 at 11:39 AM
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STRAILER
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I see, so the codes are C1237 and B1236:

The C1237 and B1236 codes you mentioned are specific to the Anti-Lock Brake System (ABS) and the Stability Control System on your vehicle. Here's what each code means:

C1237 - Speed Wheel Right Rear Input Signal Missing

Possible causes of B1236: Damaged or faulty mirror vertical switch.

So, I would replace the right rear wheel speed sensor and then clear the codes. Check out the images (below). Please let us know how it goes.
Aug 7, 2023 at 9:41 AM
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DAN ONDO
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Hello Ken,

Thank you for all this information.
Well received I will change this sensor and see what will happen.
In my country it’s a little difficult and expensive to find the spare parts for this Tucson. I have a friend on vacation in Houston right now: do you know where I can order it and have it deliverd to him?

Thank you again,

Dan
Aug 10, 2023 at 6:45 PM
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STRAILER
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Here is one on Amazon with the hub bearing for $51.00:

https://amzn.to/3qv6HR1

Please let us know how it goes.
Aug 11, 2023 at 10:12 AM
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DAN ONDO
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Guys,

When I opened the hood of the car, I found something extraordinary (lmao).

The hydraulic ABS with the ref 58920-2S310 R15 is still next to the engine but disconnected and bypassed by another one with different ref 58920-D3100 H2.
I have to take a picture to show you the "trick"

Do you think this could explain the error codes observed ?

Dan
Aug 12, 2023 at 4:26 AM
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STRAILER
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Yes, that can be a problem, it looks like the wiring is damaged as well. Here is a guide to help test the connections and the traction control and BAS wiring diagrams so you can see how the system works:

https://www.2carpros.com/articles/how-to-check-wiring

It looks like there is a set up procedure that must be done when changing out the ABS module. Check out the images (below). Please let us know what happens.
Aug 14, 2023 at 10:50 AM
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DAN ONDO
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Thank you, Ken.
First of all, I have to order the right abs module.
The ones I have now have two different references. Are they both okay for my car? My VIN is KMHJ381ADJU654807.
As it’s a Korean Tucson I’m not sure you will have access to the right parts number.
Aug 14, 2023 at 11:43 AM
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STRAILER
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Only the dealer can tell you that. I don't have that information, sorry.
Aug 15, 2023 at 8:27 AM
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DAN ONDO
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Yes, thank you anyway.
I will keep you updated.

Thanks
Aug 15, 2023 at 9:04 AM
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FATMIR ELEZI
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Hello Sir,

I have a 2008 Toyota Auris 1.4 Diesel D-4D Automatic transmission and it is the second time that while driving it is going on N (Neutral) shift. I stopped the car and turn off the engine for a while and after that, I turned it on, and the car started moving.
I went to check the error code from ECU with computer and find that active alarm was C1237 Speed Sensor Rotor (see the pic).
I want to know what to do.
- Shall I replace the Speed sensor?
- Where is located this Speed Sensor?
- Is there a possibility to clean the Speed Sensor since alarm disappears after the car engine turned off and then turn on again?

Best regards,

Fatmir
Nov 30, 2023 at 9:28 AM