Steering angle sensor issue

[l3n0x]

So here we go again, another probably faulty sensor on my hundy. (I'm starting to lose count)

Anyway, the issue is, after turning the ignition on and steering wheel straight ahead, sometimes it measures ~0 degrees, sometimes +38, etc..
It's almost like it resets after every ignition cycle, or I don't know.

I've tried resetting it manually (unplug it, turn ign on, then off, then plug back in), but that didn't stop the odd behaviour.

Anyone else has experienced this?

 

[badlander]

I'm not sure if it would help or not but I would try a Zero Point Calibration, if you havent already.

 

[l3n0x]

I'm not sure if it would help or not but I would try a Zero Point Calibration, if you havent already.

I don't have VGRS - and I think that's the ones that can do zero point calibration, or am I wrong?

 

[mmm635]

I don't have VGRS - and I think that's the ones that can do zero point calibration, or am I wrong?

1999 lx470 steering wheel angle affect ahc?

 

[l3n0x]

1999 lx470 steering wheel angle affect ahc?

Thank you, but:
I don't have VGRS to perform a calibration with techstream.
I've tried resetting it manually (unplug it, turn ign on, then off, then plug back in), but that didn't stop the odd behaviour.

 

[mmm635]

Thank you, but:
I don't have VGRS to perform a calibration with techstream.
I've tried resetting it manually (unplug it, turn ign on, then off, then plug back in), but that didn't stop the odd behaviour.

I referenced that so you could see post#2. Did you turn the opto sensor when you did it? This guy has AHC with no VGRS and did this...

Another local cruiserhead had the same problem, and opened up the steering wheel and opto-sensor assembly. He examined the possibility of turning the opto-sensor mechanically, and found it could only be turned 180 deg. But, after disconnecting the sensor and turning on ignition without sensor; when connecting the sensor again, the reading was zero.

 

[l3n0x]

I referenced that so you could see post#2. Did you turn the opto sensor when you did it? This guy has AHC with no VGRS and did this...

Ah I see, thank you!

No, I have not yet opened the steering wheel (I'd like to avoid that, because I don't like screwing with the airbag).

Anyway, this is what happens:

1, Techstream reads let's say 30 deg when wheel is pointing forward.
2, I turn the wheel left, so TS reads 0 deg
3, Turn off ignition, pull sensor connector
4, Center the wheel, turn on ignition
5, TS now correctly reads 0 deg, while steering wheel is pointing forward.

HOWEVER ( ) :

If I then let's say turn the wheel 90 deg to the right (TS reads 90 deg correctly), and turn off the ignition, DON'T pull the connector, turn ignition back on, TS now reads 0 deg, while wheel is 90 deg to the right, and reads -90 deg if I recenter the wheel..

The other scenario that seems to screw it up is if let's say the wheel is centered and TS reads 0 deg, turn the ignition off, then turn the wheel 30deg right, turn the ignition on, and it will now read 0 deg - while the wheel is 30 to the right, so after I center it, it reads -30.

Edit: I think the two last ones contradicts eachother, so will have a look later what exactly is happening. It’s just that it’s 40degC outside and the car is parked in the sun, so it’s not fun experimenting in it right now

 

[l3n0x]

Okay went out, here are my - IMO very interesting findings:

1, Let's say the steering wheel is pointing straight ahead, and I'm not touching it at all.
- In this case, every time I cycle the ignition, the angle read by TS decreases ~5-10 degrees. So if I turn the ignition on/off 3-4 times, it will be below -30 degrees, even though I've started from 0. (not touched the steering wheel)

2, To reset it, let's say it's at -30 degrees, I turn the steering wheel left 30 degrees, so TS now reads 0 degrees. I turn off the ignition, center the wheel, turn ignition back on and BAM it's reading 0 again, wheel centered.

Soooo.. I don't know what's going on, because okay, I understand that I must not touch the wheel normally when ignition is off, as there is no way for the sensor to register movement without power & remembers the last position, but the drift of the angle on every ignition cycle is a mystery for sure.