MarsdenDean Posted August 23, 2013 Report Share Posted August 23, 2013 Hi all, I have a lexus gs 450h sport with adaptive variable suspension and active stabilizer suspension. i have been back to lexus bolton over 20 times over the last 2 years because of the drive, it's a long story but i the car was pulling all the time and steering where it wanted, i used to love driving the car as it was excellent and i could do speeds in it without worrying, now i'm lucky if i hit 80 as it feels really insecure. They keep mentioning tyres and geometry and i am now on my third set of different tyres and had the geometry done myself at nigel llaings bolton (who i must say were excellent). the tyres and geometry did not make any difference so lexus have so far changed the front motor (£3000), steering column (£2500) rear motor (£4000) and steering angle sensor £?. Bolton had said they could not fix the problem and i would be better taking it to lexus carlisle where i bought it from. since much complaining bolton are now bringing in a lexus area technician but i am worried as there will be him, the center principle, the after sales manager and the master technician in the meeting and i think they may be trying to bully me into thinking the car is ok. Peter at llaings suggested i contact this forum for any help i can get. the car leans to one side on the rear and this can vary between 2mm and 30mm under the same conditions and no load. The pulling gets worse and it can be to the left or right after country roads or roundabouts even cause the problem. Any advice or help would be much appreciated Quote Link to comment Share on other sites More sharing options...
Tony Posted August 23, 2013 Report Share Posted August 23, 2013 I take it it's air suspension?...... If yes then my thoughts are toward the actuators. Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted August 23, 2013 Author Report Share Posted August 23, 2013 it,s got actuators on but i think off reading up they have 3 motions that let the oil run through different chambers with rotary valves. will the actuators give different height if one is stuck was my thinking but i'm a heating engineer so technically minded but not too clued up on how the system works fully Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted August 23, 2013 Author Report Share Posted August 23, 2013 peter said tony is the man to find the problem if he gets the grit between his teeth. working in east sussex from 2nd till 13th sept so if you like a challenge i can bring the car for a look Quote Link to comment Share on other sites More sharing options...
Tony Posted August 24, 2013 Report Share Posted August 24, 2013 I can't test the actuators only offer a heads up. Clearly there isn't a leak in the pressure system since it's not self healing, so my thoughts are the control for the height is being misinformed hence the variable height. Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted August 24, 2013 Author Report Share Posted August 24, 2013 http://m.clublexus.com/forums/showthread.php?t=664548 the asss system uses a motor which twists the anti roll bars to make it corner flatter, and it also uses an adaptive suspension system which controls the dampers. its controlled via many different sensors and ecus but it's not an air system :-/ Quote Link to comment Share on other sites More sharing options...
Tony Posted August 24, 2013 Report Share Posted August 24, 2013 So there's no direct control at the suspension toward adaptive body height? Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted August 24, 2013 Author Report Share Posted August 24, 2013 I'm unsure! from my understanding after reading many lexus tech documents is : the car adjusts the dampers according to what certain sensors are telling the actuators to adjust the dampers to. A bumpy road would relax the dampers to provide a smoother ride, setting off fast would adjust them stiffer to control lift on the front end. It uses yaw sensors, ,dive sensors, , steering input settings etc to calculate what each dampener should be doing. This is the avs system. The asss controls the front and rear anti roll bars by twisting it to control body roll through corners etc. this is via a motor so the roll bar is always changing its position depnding on how the csr is being driven. This also is calculated from the same sensors (I think) as the avs system. hope this helps a little ! Quote Link to comment Share on other sites More sharing options...
Tony Posted August 24, 2013 Report Share Posted August 24, 2013 So damper adjustable only...... You need to ask if additional damper pressure could extend the damper shaft. Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted August 24, 2013 Author Report Share Posted August 24, 2013 I'm struggling to find information from the internet about this AVS (Adaptive Variable Suspension) and ASSS (active stabilizer suspension system) but i do have around 60 pages of technical information that i have downloaded from http://www.lexus-tech.eu/ to try and understand about these systems. If the above answer is yes, would this cause the car to lean sometimes, and be level at other times depending on the road surfaces or road i have driven ie twisty country road or motorway? Also would the incorrect ride height cause it to pull to either left or right and the wheel not remain central at times? Quote Link to comment Share on other sites More sharing options...
parthiban Posted August 27, 2013 Report Share Posted August 27, 2013 Hi Dean, how are things? Sorry to hear about the issues with the car, I remember looking at the GS Sport a few years ago, and yes it isn't air suspension, it has active body control. From what I remember it would use it's sensors to measure body roll and then actively adjust the suspension to stop it leaning. Seeing as it's leaning when it shouldn't, my first thought would be to check whether those sensors are all working properly, and then probably the ECU next. I highly doubt it's the motors, to me it sounds like the car thinks it is leaning when it isn't. Quote Link to comment Share on other sites More sharing options...
Tony Posted August 28, 2013 Report Share Posted August 28, 2013 Indeed.... Quote Link to comment Share on other sites More sharing options...
SMARTLY Posted August 28, 2013 Report Share Posted August 28, 2013 Are the sensors easy enough to swap sides to see if the lean swaps over? Quote Link to comment Share on other sites More sharing options...
Tony Posted August 29, 2013 Report Share Posted August 29, 2013 That or the ECU command. Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted September 13, 2013 Author Report Share Posted September 13, 2013 sorry for the very late responses and thanks the car is due in on Tuesday and I am meeting 5 lexus members of staff, ranging from a mechanic to lexus area manager I will ask them about swapping the actuators and see where things go from there. Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted September 13, 2013 Author Report Share Posted September 13, 2013 well ill ask them about faulty sensors. The steering angle sensor has already been changed and we have a full electrical print out about what values they should be testing for, but seams lexus Bolton can't check using the procedures outlined by lexus UK for some odd reason, they just like throwing £££ at the car. so far around 17k has bee spent trying to sort this problem out Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted September 13, 2013 Author Report Share Posted September 13, 2013 well ill ask them about faulty sensors. The steering angle sensor has already been changed and we have a full electrical print out about what values they should be testing for, but seams lexus Bolton can't check using the procedures outlined by lexus UK for some odd reason, they just like throwing £££ at the car. so far around 17k has bee spent trying to sort this problem out Quote Link to comment Share on other sites More sharing options...
Tony Posted September 14, 2013 Report Share Posted September 14, 2013 Tuesday should be an interesting day..... One more point does the car have torsion bars? Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted September 16, 2013 Author Report Share Posted September 16, 2013 I can't see anywhere that mentions them on the lexus Quote Link to comment Share on other sites More sharing options...
Tony Posted September 16, 2013 Report Share Posted September 16, 2013 Can you check with them when it goes in.... I would hope it doesn't because if it does have them it would be a monumental error they are overlooked, Quote Link to comment Share on other sites More sharing options...
parthiban Posted September 16, 2013 Report Share Posted September 16, 2013 Given the symptoms this has got to be an electronic issue rather than a mechanical one - hope they find the cause. Quote Link to comment Share on other sites More sharing options...
Tony Posted September 16, 2013 Report Share Posted September 16, 2013 The "randomness" suggests electronic? Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted September 16, 2013 Author Report Share Posted September 16, 2013 If it does what could be the problem Tony? Your help has been great, can't thank you enough Quote Link to comment Share on other sites More sharing options...
Tony Posted September 16, 2013 Report Share Posted September 16, 2013 Actuators or self leveling pick-up point communication error ( mechanical ) Quote Link to comment Share on other sites More sharing options...
MarsdenDean Posted September 16, 2013 Author Report Share Posted September 16, 2013 the last one does that relate to the torsen bars ? Quote Link to comment Share on other sites More sharing options...
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