LWS/DSC Diagnostic Question

[Fatcat]

Hello, I hope all is well with you guys. I've been busy with life and missed this forum

To start, I have had my ECU/DME replaced and reprogrammed in the past, which I've heard could be a cause of this issue.

I've had a steering angle sensor problem for a while now, but regardless, I wanted to fix it. Before, the live data showed -1440 for the steering angle (assuming this meant it could not read it). Tonight I went to recalibrate my steering angle sensor in hopes of fixing the problem.

When I opened the menu, the live steering angle data showed the correct data when steering. I recalibrated the steering angle sensor, and the code went away for a few seconds, then I started steering left and right hard to see if it would come back (it came back).

My question now is, where should I start looking now? I want to diagnose this problem and fix it myself. From the looks of it, to my noob brain, the steering angle sensor is fine and can be read. however im still getting these error codes

LWS 04 Slider fault (adjustment operation)
DCS/DXC: 5EB1 Present, Steering angle sensor supply
5DEB not present (not present???) insignificant clear fault memory.

I am genuinely stuck and confused, im considering removing the sensor itself and checking it out, I would rather not. But I'm not sure what options I have left.

Thanks for any help you guys offer!

[andrewwynn]

90+ percent chance the sensor is shot. Usual cause it's the wiper is worn out. There's a repair kit you can buy on eBay. Your symptoms exactly match worn out sensor other than it's not normal to have power loss which can be a connector or wiring problem. Watch the live data more. If the wiper is bad you'll get jumping data. Graph the live data if you ever get a step in the value you just confirmed it's shot.


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[Fatcat]

Originally Posted by andrewwynn

90+ percent chance the sensor is shot. Usual cause it's the wiper is worn out. There's a repair kit you can buy on eBay. Your symptoms exactly match worn out sensor other than it's not normal to have power loss which can be a connector or wiring problem. Watch the live data more. If the wiper is bad you'll get jumping data. Graph the live data if you ever get a step in the value you just confirmed it's shot.

Hello Andrew thanks for the response. I checked the live data again this morning and to my eyes, it's not really stepping big digits. Maybe it will skip from 4 to 6, but nothing more than two digits. Is that what you meant by jumping data? and by repair kit, I asssume you are talking about this? My question is, if the sensor is bad how come it still shows live data? I don't mind opening the panel to remove the sensor but I want to make sure the sensor is actually bad and the error isn't showing because of my previous DME replacement. Thanks!

[andrewwynn]

When you steer it should just be a smooth graph no jumps. Usually it will jump to any different value and back eg -130° then -150 and back to -130. The -1440 likely represents open circuit akin to outdoor temp reading -40.


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[andrewwynn]

Most bad sensor just means at times an intermittent reading. One millisecond of a pause in the value will set the error it’s a critical safety system so it has zero fault tolerance.


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[80stech]

The controller reads the sensor much faster than you can see on the display so can set a code even if it "looks" smooth. Back in the day I built a computerized test jig for Throttle, EGR, etc. wiper sensors that operate the same way, and sampling at a 1000 measurements per second and graphing could easily pick out a bad sensor that would normally be missed.

[Fatcat]

Originally Posted by andrewwynn

When you steer it should just be a smooth graph no jumps. Usually it will jump to any different value and back eg -130° then -150 and back to -130. The -1440 likely represents open circuit akin to outdoor temp reading -40.

It does not jump that big, it's still not as smooth as it should be, but that's most likely my scanner reading it like that. As for the -1440 reading, I have no idea why it went back to "normal" after showing a faulty reading for months.

Originally Posted by andrewwynn

Most bad sensor just means at times an intermittent reading. One millisecond of a pause in the value will set the error it’s a critical safety system so it has zero fault tolerance.

Let's say if one millisecond of a pause will set an error, could there be something in the middle of the LWS that can also cause this issue, or should my main concern just be the Steering Angle Sensor for now?

Originally Posted by 80stech

The controller reads the sensor much faster than you can see on the display so can set a code even if it "looks" smooth. Back in the day I built a computerized test jig for Throttle, EGR, etc. wiper sensors that operate the same way, and sampling at a 1000 measurements per second and graphing could easily pick out a bad sensor that would normally be missed.

So basically, the ACTUAL "polling rate" or "refresh rate" is much higher than what I see on my scanner. This makes sense because it would take a decent amount of power to actually show each "refresh" on a battery powered scanner (also your test jig sounds useful)

I don't think I can do much except for opening the sensor and seeing if everything inside is alright. I've seen on another forum that the "needles"/"pins" or whatever they are can get bent with pictures shown, so that is most likely my next thing to diagnose. I'll also clean it while im in there and probably purchase a repair kit if I see anything wrong. Thanks Guys!

[80stech]

The sensor is almost certainly the problem(or at least one of them), especially since you have done some checking around the wiring. I think it's a fair bit of work to get to and replace it so you might want to have a new OE sensor on hand instead of patching up the old one.

[Fifty150hs]

Originally Posted by 80stech

The sensor is almost certainly the problem(or at least one of them), especially since you have done some checking around the wiring. I think it's a fair bit of work to get to and replace it so you might want to have a new OE sensor on hand instead of patching up the old one.

I agree. Sounds just like a bad SAS. Mine was the same. I replaced it. Not a fun job. No job working under the dash is fun. It's pretty straight forward. Make sure you mark the steering shaft and coupling so you clock it properly when you put the two back together or the wheel will be turned when wheels are straight. Don't ask me how I know.

[andrewwynn]

You can and i have bent the wipers on similar devices to bring them back to behaving.

Dirty contacts self clean from wiping when they are aged enough they can clean up good enough to work ok for a while then suddenly blip a bad reading.

You can also likely just treat the contact surfaces with deoxit pro gold and have instant fix.


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