TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Steering Assist Reduced

Discussion in 'Model X: Driving Dynamics' started by gnguyen, May 24, 2017.

  1. gnguyen

    gnguyen Member

    Joined:
    Nov 28, 2013
    Messages:
    24
    Had this happen to me today. While driving to drop the kids off, occasionally the steering wheel would for a brief moment get very stiff, then go back to normal. AP2 AutoSteer never became available, despite being available on the same roads the previous day.

    When I got to school, driving over the curb and over the bump of the security gate rail apparently caused all power steering to just fail, and the wheel stayed stiff and the car flashed a "Car Needs Service - Steering Assist Reduced" sign on the dash and on the touchscreen. I was pointing straight at a handicapped spot so I just drove right into it and parked, dropped off the kids and went back to call Roadside Service.

    ETA was an hour for someone to come take the car. Before they called me back I was fiddling with various resets and leaving the car/coming back, pressing the brake, and the steering came back. I decided to take the car myself straight to the service center.

    When the steering assist is off, it's WAY more stiff than an old school manual steering car. You will need both hands to turn the wheel. Luckily it briefly triggered off only one more time before getting on the highway, and I got to the service center safely. There they wanted to test drive it, and the technician could feel the issue happen occasionally. He was able to trigger it again completely by going over a few speed bumps. AP2 AutoSteer never became available again either.

    The initial diagnosis is a loose wire somewhere that's causing the power steering to fail. A few people have had this issue with their Model S's as well, looking around the forums. The service center is going to take a pretty careful look, as its a serious safety issue.

    I'm pretty disappointed that this is a thing. If it's a loose wire, there's some shoddy assembly line work happening, or some pretty poor quality control. I'm just glad nothing scary happened, as it could have.
     
    • Informative x 1
  2. Yinn

    Yinn Member

    Joined:
    Nov 15, 2016
    Messages:
    540
    Location:
    Behind you
    Any idea which wire it is? A couple of us have had this happen, but with no error lights. It's been giving an impression of a "dead spot" in the steering for AP2's.
     
  3. MS16

    MS16 Member

    Joined:
    Jan 23, 2017
    Messages:
    330
    Location:
    Calif
    Keep us posted, something as significant as a steering problem is an item you definitely hope they find a hard failure, and not just a repair based on the technician's speculation.
     
  4. gnguyen

    gnguyen Member

    Joined:
    Nov 28, 2013
    Messages:
    24
    They are going to be pretty thorough because it's a safety issue. I hope it's simple though and not something more difficult an issue to solve. It seemed like something they had encountered before.
     
  5. gnguyen

    gnguyen Member

    Joined:
    Nov 28, 2013
    Messages:
    24
    Posted this in the Model S thread on the same subject:

    I got the car back today from service. They said they found the loose power steering ground connection. Reattached, they took it out for a test drive over some bumps, checked again and it didn't move. So they called it fixed.

    It seems fine right now. AutoPilot fully functional and no steering wheel lockups. Let's hope it's fixed for sure.

    The tech said that it is a pretty rare issue, which is good news for everyone else.
     
  6. Yinn

    Yinn Member

    Joined:
    Nov 15, 2016
    Messages:
    540
    Location:
    Behind you
    Funny, in the S thread I stated that it felt like a failing power steering pump...now I have to find where that ground is to make sure mine is tight.
     
  7. MS16

    MS16 Member

    Joined:
    Jan 23, 2017
    Messages:
    330
    Location:
    Calif
    Did you have the Service Center look at it?
     
  8. Yinn

    Yinn Member

    Joined:
    Nov 15, 2016
    Messages:
    540
    Location:
    Behind you
    Yup.

    Good: They found a malfunctioning wheel speed sensor - which surprisingly didn't trigger any warning lights.
    Bad: It didn't solve the problem.
     
  9. MS16

    MS16 Member

    Joined:
    Jan 23, 2017
    Messages:
    330
    Location:
    Calif
    Are they still trying to find the problem?
     

Share This Page