IS-F / Sport Steering ECU
03-04-14, 10:16 AM
#197
Great feedback and very interesting observations! Would this lead you or anyone else to believe that the ABS Skid Control "VDIM" box is similar if not the same between ISx50 and ISF and its only the Steering ECU making the difference here as reported by so many users?
I would have thought that the ISF would use a more advanced VDIM ecu due to the increased functionality of SPORT and the aa80e (if it even applies here). I realize part numbers vary between the IS and ISF skid control vdim ecus but wire pins going into the box look shared upon first glance on TIS. I need to renew my subscription but this is something I def. want to confirm as I have access to purchase an ISF skid control ecu (combined with ISF steering ecu) to replace my primitive 2006 IS350 vdim ecu.
I would have thought that the ISF would use a more advanced VDIM ecu due to the increased functionality of SPORT and the aa80e (if it even applies here). I realize part numbers vary between the IS and ISF skid control vdim ecus but wire pins going into the box look shared upon first glance on TIS. I need to renew my subscription but this is something I def. want to confirm as I have access to purchase an ISF skid control ecu (combined with ISF steering ecu) to replace my primitive 2006 IS350 vdim ecu.
I have also pondered that question as well while I've been partaking in more spirited driving in order to compare the handling differences with the different steering ECUs.
With the IS-F steering ECU, there is a noticable difference in the speeds and steering angle that you are able to take in a corner before the VDIM system intervenes. I noticed that with the ISx50 ECU, if you try to accelerate hard out of a corner (with VDIM fully on), the system will only permit a certain degree of steering before it cuts off any further input (I assume for stability purposes) which would lead to potential understeer. This is mostly not the case now with the IS-F steering ECU. On the streets, the only time I still get system intervention is when I'm making 90 degree turns around a corner.
I do believe that the IS and ISF skid control ECUs are different and also have their own seperate algorithms. The reason I believe so is that when the VSC is turned off via the button press, the eLSD brake function does not activate on my IS350 as it would on the IS-F. On the 08-09 IS-Fs, when VSC is turned off via the long press, the eLSD will still be active and the TRAC icon on the dash will flash. So far, I have not seen the TRAC icon flash when cornering with the VSC off (which is how the ISx50 behaves by default).
My question is if the eLSD brake function even exists on the 2010+ IS-Fs as the torsen LSD was added to the 2010 model. If both the eLSD and torsen LSD co-exist on the 2010+ IS-F (and assuming that the eLSD function is controlled by the skid control ECU), then the IS and IS-F skid control ECUs would be different and potentially room for more improvement. So far, I believe that with the IS-F Steering ECU, I have most of the benefits of what VDIM Sport has to offer on the IS-F but with the lack of eLSD function with VSC off, I'm lead to believe that there are still a few subtle differences within the other ECUs that make up the entire VDIM ecosystem between the ISx50 and IS-F.
03-04-14, 02:41 PM
#198
Hey Mike,
I have also pondered that question as well while I've been partaking in more spirited driving in order to compare the handling differences with the different steering ECUs.
With the IS-F steering ECU, there is a noticable difference in the speeds and steering angle that you are able to take in a corner before the VDIM system intervenes. I noticed that with the ISx50 ECU, if you try to accelerate hard out of a corner (with VDIM fully on), the system will only permit a certain degree of steering before it cuts off any further input (I assume for stability purposes) which would lead to potential understeer. This is mostly not the case now with the IS-F steering ECU. On the streets, the only time I still get system intervention is when I'm making 90 degree turns around a corner.
I do believe that the IS and ISF skid control ECUs are different and also have their own seperate algorithms. The reason I believe so is that when the VSC is turned off via the button press, the eLSD brake function does not activate on my IS350 as it would on the IS-F. On the 08-09 IS-Fs, when VSC is turned off via the long press, the eLSD will still be active and the TRAC icon on the dash will flash. So far, I have not seen the TRAC icon flash when cornering with the VSC off (which is how the ISx50 behaves by default).
My question is if the eLSD brake function even exists on the 2010+ IS-Fs as the torsen LSD was added to the 2010 model. If both the eLSD and torsen LSD co-exist on the 2010+ IS-F (and assuming that the eLSD function is controlled by the skid control ECU), then the IS and IS-F skid control ECUs would be different and potentially room for more improvement. So far, I believe that with the IS-F Steering ECU, I have most of the benefits of what VDIM Sport has to offer on the IS-F but with the lack of eLSD function with VSC off, I'm lead to believe that there are still a few subtle differences within the other ECUs that make up the entire VDIM ecosystem between the ISx50 and IS-F.
I have also pondered that question as well while I've been partaking in more spirited driving in order to compare the handling differences with the different steering ECUs.
With the IS-F steering ECU, there is a noticable difference in the speeds and steering angle that you are able to take in a corner before the VDIM system intervenes. I noticed that with the ISx50 ECU, if you try to accelerate hard out of a corner (with VDIM fully on), the system will only permit a certain degree of steering before it cuts off any further input (I assume for stability purposes) which would lead to potential understeer. This is mostly not the case now with the IS-F steering ECU. On the streets, the only time I still get system intervention is when I'm making 90 degree turns around a corner.
I do believe that the IS and ISF skid control ECUs are different and also have their own seperate algorithms. The reason I believe so is that when the VSC is turned off via the button press, the eLSD brake function does not activate on my IS350 as it would on the IS-F. On the 08-09 IS-Fs, when VSC is turned off via the long press, the eLSD will still be active and the TRAC icon on the dash will flash. So far, I have not seen the TRAC icon flash when cornering with the VSC off (which is how the ISx50 behaves by default).
My question is if the eLSD brake function even exists on the 2010+ IS-Fs as the torsen LSD was added to the 2010 model. If both the eLSD and torsen LSD co-exist on the 2010+ IS-F (and assuming that the eLSD function is controlled by the skid control ECU), then the IS and IS-F skid control ECUs would be different and potentially room for more improvement. So far, I believe that with the IS-F Steering ECU, I have most of the benefits of what VDIM Sport has to offer on the IS-F but with the lack of eLSD function with VSC off, I'm lead to believe that there are still a few subtle differences within the other ECUs that make up the entire VDIM ecosystem between the ISx50 and IS-F.
Being that I have an 06 my ultimate decision is what VDIM ecu to implement with the 12 ISF steering ecu. Option 1 is the cheap 07+ IS350 vdim ecu (allows turn off via switch hold vs peddle dance) while Option 2 would be the 08-10 ISF vdim ecu. I'm def. purchasing a vdim ecu to replace my 06 though.
03-12-14, 10:19 AM
#200
Have you already installed and calibrated the new '12 IS-F Steering ECU? If so, are you able to provide any additional feedback?
I'm scheduled to get the cam gear recall done on my IS350 later this month and immediately afterwards, I'll be ordering the '12 IS-F Steering ECU as I simply can't resist!
After reading this thread, I'm still not 100% certain if I'm able to install the new IS-F Steering ECU at home and then safely/passively drive a few miles to the Lexus dealership to get it fully calibrated.
For those that have done this mod, any thoughts on that?
I'm scheduled to get the cam gear recall done on my IS350 later this month and immediately afterwards, I'll be ordering the '12 IS-F Steering ECU as I simply can't resist!
After reading this thread, I'm still not 100% certain if I'm able to install the new IS-F Steering ECU at home and then safely/passively drive a few miles to the Lexus dealership to get it fully calibrated.
For those that have done this mod, any thoughts on that?
05-25-14, 06:06 AM
#201
Maybe I missed it but have any of you calibrated your brand new out of the box Steering ECU with Techstream outside of the dealer? The process on TIS is straight forward but I cant get the functions to execute with my Techstream. 
Oh and for the record, I checked every pinout between the 07+ IS350 and 08-10 ISF skid control ecu and they are all the same. If the ISF vdim ecu has tighter parameters or better algorithms its not to be seen based on the wiring. I ultimately did elect to use the ISF vdim ecu on my swap though...
Oh and for the record, I checked every pinout between the 07+ IS350 and 08-10 ISF skid control ecu and they are all the same. If the ISF vdim ecu has tighter parameters or better algorithms its not to be seen based on the wiring. I ultimately did elect to use the ISF vdim ecu on my swap though...
06-13-14, 01:12 PM
#203
Slightly off topic here but; does anyone know if the ISF steering rack ratio is the same as the ISX50? On the 2011 ISF besides the steering “feel” I can’t really tell if there is a different ratio, it reacts a lot faster and feels better, but this may be just be the ECU.
06-27-14, 03:46 PM
#206
Just bought ( Sewell @$430) and installed. Had my Toyota dealer do the Techstream initilization ($134)as the steering was not programmed. There is a very noticable improvement in steering responce and feel on my 09 IS350 with the (Power/Sport) button depressed. I have a track event at Thunderhill this July 18th, I'll let everyone know what the difference is.
07-06-14, 05:07 PM
#207
So I can really feel a difference in the car. I used to spin the Passenger wheel like CRAZY when I floored it turning right from a stop. That is now almost completely gone! The steering is MUCH tighter and responsive when driving over 60mph. Can't wait to try it on the track in 2 weeks. (This is all with the Power/Sport) button engaged.
07-10-14, 08:46 AM
#208
I just purchased and installed 89650-53041 into my 2007 is350. When I reconnected the battery and turned the car on there was no power steering at all. I was told this is not normal. So i disconnected battery, waited 5 min and reconnected, didn't work. I disconnected the ECU and reconnected it back, still didn't work.
Then I reconnected the stock ECU and started the car. I still have no power steering and now the red "p/s" light came on. Im a bit frustrated at this point and looking for any suggestions.
Btw I did manage to break the two little nipple tab things that hold on the connector, but I ensured that I pushed the connector on as far as it would go. Hoping this has nothing to do with it.
Then I reconnected the stock ECU and started the car. I still have no power steering and now the red "p/s" light came on. Im a bit frustrated at this point and looking for any suggestions.
Btw I did manage to break the two little nipple tab things that hold on the connector, but I ensured that I pushed the connector on as far as it would go. Hoping this has nothing to do with it.
07-10-14, 08:51 AM
#209
It sounds like you do not have the connector installed all the way, just pushing it on will not make a connection, the last movement of the locking arm is what actually gets the connector in far enough for the terminals to make contact.
Jeff
Jeff
07-10-14, 08:59 AM
#210
Jeff, thanks for the suggestion. The connector I question the most is the one nearest the engine. Here is a pic, can you tell if it looks like its not fully engaged. Had I know I was going to have this issue I would have taken a pic of the original before starting, just for comparison.