1999 lx470 steering wheel angle affect ahc? (1 Viewer)

[Nick T]

Hello guys,
First post. Great forum, I have found alot of what I need reading here. Just bought a 1999 lx470 and have been base lining it. T belt water pump all fluids have been done. While hooking up tech stream to get my ahc pressures noticed my steering angle sensor reads 80 degrees off. Rack was replaced prior to my ownership. I know newer lx470 with vgrs couple the left and right front shocks when the steering is over 30 degrees for handling. Cannot find anything stating it does this with older lx.
Can anyone with a FSM or knowledge let me know if i need to get my steering angle back in spec and how can i do this?
Thank you

 

[uHu]

Same thing on the non-vgrs, when it comes to the ahc-function. With steering angle over 30 (or was it 35) degrees (and not standing still), the hydraulic connections between left and right shocks are blocked, in order to reduce roll when cornering.
I haven't found out how to reset it to zero - it's definitely not in the manual. 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.
I'll have to look into this one day, as my reading is just under 30 deg wrong, and it does affect cornering to one side.
As I understand it, on the vgrs-versions, the angle is software resettable (something like putting the actuator int a free-spooling mode and turning the wheel back and forth in a special way), but no such thing on the non-vgrs.

 

[Nick T]

Took apart the steeriung column. Couldn't disconnect the steering angle sensor, the wires are tucked up above some other connections, so I disconnected every wire harness to the steering column except the air bag sensor. Turned the ignition on and checked techstream, still off 80 degrees. Put the rig back together and took it for a test drive, after the drive hooked up techstream again, it now says 20 degrees? Not sure if it is some worn bushing or ball joint , everything feels solid but at least now it is within the 30-35 degree range. Wonder why it still said 80 after the disconnect but now says 20 after the test drive.

 

[PADDO]

What MY do you have? ( edit: just reread your original post, '99 got it) I corrected a 339 degree angle (techstream steering angle sensor) by doing a VGRS calibration and system reinitialization. Whilst stationary, after the calibration, the 339 degree angle was still reported until I took it for a drive and the system sorted itself out - you need to check the "straight angle flag" is valid to confirm all is OK. Now it's close to 0 degrees. 339 degrees, as displayed via techstream in a vgrs system, equals about 180 degree of steering wheel angle whilst stationary. Driving whilst graphing steering angle and SLFG/SLRG (to compare wheel angle and correct AHC gate valve operation) in techstream showed everything seemed balanced and operating as designed. I.e. With more than 35 degrees of actual front wheel angle the gate solenoids operated as expected.

 

[Vampo]

Hi Paddo,

Would you be able to post the steps to reset (correct) the steering angle sensor reading (techstream). I have a reading of 567 degrees .

 

[PADDO]

In Techstream you hit the VGRS tab and go into the utility function then follow the prompts. Follow that with a slow left 90/center wheel/right 90/recentre for 3 seconds. Then Slow left and turn engine off and keep left turning force on for another 3 seconds. Repeat 15 times, yep 15. Go for a drive and recheck in Techstream data list, look for "straight angle flag = valid" and hopefully you have 0 or very close to 0 degrees for the SAS. I'd never seen 339 degrees reported before, I also had some unexpected numbers in the serial and parallel data fields that went back to zero after resetting.

 

[Vampo]

Thanks Paddo. I'll try this.

 

[Nick T]

Paddo,
The model year is listed in the thread title as well as the first post. 1999 LX470, which does not have VGRS or VSC so you cannot do a zero point calibration or zero the steering angle in techstream. It would seem the way to zero the steering angle is to follow uHu's advice and disconnect the sensor, turn ignition on etc.

 

[PADDO]

Paddo,
The model year is listed in the thread title as well as the first post. 1999 LX470, which does not have VGRS or VSC so you cannot do a zero point calibration or zero the steering angle in techstream. It would seem the way to zero the steering angle is to follow uHu's advice and disconnect the sensor, turn ignition on etc.

Yep, got it. I owned a '98 LX previously. Sometimes salient info is missed when reading threads on a phone screen. Sounds like you've got it all covered. As a matter of interest hook up techstream and graph steering angle and SLFG whilst driving and cornering.

 

[Vampo]

Hi Paddo,

Just tried following the instructions. However according to tech stream you need to keep the engine off during this procedure and they tell to turn the steering 5 degrees. ( well atleast that's what I gathered from their prompt).

Am I to start the engine and do the procedure you mentioned above and stop the engine after each . I.e. 15 time start, procedure and stop?

 

[PADDO]

Yep follow the Techstream screen prompts and then when it's done you do x15 steps. It's called the learning validation process iirc. Its 15 start stop cycles, sounds crazy but that's what all the DI literature says.