Power Steering Woes - Assistance Needed (MDPS)

[Lemming867]

Hello, all! I'm hoping someone in this forum has had similar issues or is more knowledgeable than me and can provide some guidance.
2015 Genesis Sedan, RWD, 3.8. Owned it since 2018 and 25k miles
It now has ~75k miles and no warranty, extended or factory.

Issue: Started the car up the other day and the steering fault light was on, there is no power steering - the wheel is very hard to turn. No noises or other weird behavior when I drive it now or when it was driven the day before. I did some looking around on this forum and other various ones - and there's not really a lot of information out there regarding these vehicles and this warning light.

However, I did find a neat video about Hyundai's MDPS system and its complexity (wheel turns a torsion rod which casts a shadow on a sensor to detect which way the wheel was turned, blah blah blah). Absolutely crazy. I found some hyundai/kia threads for other models and there's some known issues with bushings and things like that.

Anyways - here's what I've done so far:
1. Disconnected battery to reset codes. Came back instantly.
2. Visually inspected MDPS Fuses (10A for the ECU and 120A for the motor I think)
3. Visually inspected wires that are easily visible to/from the MDPS (three harnesses go into the MDPS "box" and appear to be fine). Location of the MDPS motor is straight below the air intake box but all the way down to the undercarriage shield
4. Purchased a super nice scan/diagnostic computer, and found the DTC code to be C1687 "CAN Time-out MDPS"
5. Used the computer to clear all stored codes manually

But the same symptoms still persist and the light is still on.

Here's a few things I've found online that mention the code as it relates to MDPS - but none of them relate to the Genesis sedans.
TSB: https://static.nhtsa.gov/odi/tsbs/2022/MC-10209439-0001.pdf - solution is replace MDPS ECU
TSB: https://static.nhtsa.gov/odi/tsbs/2020/MC-10180981-0001.pdf - solution is to check wires and replace parts if wires are good

So - I'm lost... Do any of these TSB's even apply since they don't list the genesis sedan?

What I'm going to do:
1. Get under the car and closely inspect wiring and wiring harnesses after removing the undercarriage shield
2. Check any visible ground points to see if it's a grounding/electrical issue (I doubt it since multiple circuits usually share a ground and this issue is isolated to power steering circuit)
3. Any ideas???....


I'm freaked out because if the system needs to be replaced, it appears to be ~$4k just for the PART without labor!!!
Big sad and coming from a 2002 Jeep wrangler - yes it breaks more frequently, but you can usually look at stuff and identify stuff that's broken, then turn a wrench to fix it, and I'm very good at that! This just makes me angry. Before figuring out the whole MDPS thing, I was like... steering issue: ok I can replace a hydraulic pump, do a fluid flush, and all that stuff, so let me grab my wrenches.... but NOPE!


Thank y'all in advance and I'll do my best to update this thread so hopefully it'll help someone in the future once I get to the bottom of it!!

 

[Lemming867]

Hello, all! I'm hoping someone in this forum has had similar issues or is more knowledgeable than me and can provide some guidance.

2015 Genesis Sedan, RWD, 3.8. Owned it since 2018 and 25k miles

It now has ~75k miles and no warranty, extended or factory.



Issue: Started the car up the other day and the steering fault light was on, there is no power steering - the wheel is very hard to turn. No noises or other weird feelings when it was driven the day before. Not good, as I did some looking around on this forum and other various ones - and there's not really a lot of information out there regarding these vehicles and this warning light.



However, I did find a neat video about Hyundai's MDPS system and its complexity (wheel turns a torsion rod which casts a shadow on a sensor to detect which way the wheel was turned, blah blah blah). Absolutely crazy. I found some hyundai/kia threads for other models and there's some known issues with bushings and things like that.



Anyways - here's what I've done so far:

1. Disconnected battery to reset codes, no luck

2. Visually inspected MDPS Fuses (10A for the ECU and 120A for the motor I think)

3. Visually inspected wires that are easily visible to/from the MDPS (three harnesses go into the MDPS "box" and appear to be fine). Location of the MDPS motor is straight below the air intake box but all the way down to the undercarriage shield

4. Purchased a super nice scan/diagnostic computer, and found the DTC code to be C1687 "CAN Time-out MDPS"

5. Used the computer to clear all stored codes manually



But the same symptoms still persist.



Here's a few things I've found online that mention the code as it relates to MDPS - but none of them relate to the Genesis sedans.

TSB: https://static.nhtsa.gov/odi/tsbs/2022/MC-10209439-0001.pdf - solution is replace MDPS ECU

TSB: https://static.nhtsa.gov/odi/tsbs/2020/MC-10180981-0001.pdf - solution is to check wires and replace parts if wires are good



So - I'm lost... Do any of these TSB's even apply since they don't list the genesis sedan?


What I'm going to do:

1. Get under the car and closely inspect wiring and wiring harnesses after removing the undercarriage shield

2. Check any visible ground points to see if it's a grounding/electrical issue (I doubt it since multiple circuits usually share a ground and this issue is isolated to power steering circuit)





I'm freaked out because if the system needs to be replaced, it appears to be ~$4k just for the PART without labor!!!

Big sad and coming from a 2002 Jeep wrangler - yes it breaks more frequently, but you can usually look at stuff and identify stuff that's broken, then turn a wrench to fix it, and I'm very good at that! This just makes me angry. Before figuring out the whole MDPS thing, I was like, ok I can replace a hydraulic pump, do a fluid flush, and all that stuff, so let me grab my wrenches.... but NOPE!





Thank y'all in advance and I'll do my best to update this thread so hopefully it'll help someone in the future once I get to the bottom of it!!