retrofitting cruise control to IS200 manual...
retrofitting cruise control to IS200 manual...
From first days of owning a IS200 I really wanted cruise control for it, I looked and even tried to go OEM way adding cruise stalk to steering wheel, but later I found out that wires from stalk don't go anywhere further than steering column, so that didn't work...
Later I was looking at aftermarket cruise kits, but they go around 100+ pounds, have ugly controls, actuators and I think they are nothing near OEM parts quality wise.
In my country (Latvia) older cars still are very popular and especially bmw's, vw's and audi's. so the parts are cheap and widely avelable. I was looking for a cruise control actuator and wanted to programm my own control unit and put it in my car. I even wrote a program that controls actuator with PID algorithm, but never tested it in car. I knew that bmw uses seperate ECU's for almost everything in the car and also for cruise control so I started searching around.. A nice thing also is that older cars (e30, e36) do not have any kind of body or ecu communication bus like CAN or MPX, so that system can work as complete stand-alone unit. (cruise module must be coded if bought brand new from dealer. If the module has been used in a car before, it should work straight away) ahother good thing is that it does not matter if the car was auto or manual, ecu's are the same, there are just minor differences in wiring.
so - I got myself a cruise actuator from a e39 for 15 euros and ECU from 96' e36 auto for another 15 euros, looked up for wiring diagram online and started bench-testing.
For OEM look I bought cruise stalk and steering wheel back cover from IS300 for another 15 euros.
I got cruise control working on my desk using laboratory signal generator as speed input for ecu.
Vehicle speed
Clutch pedal
Brake pedal
are the three things needed for cruise to work
this cruise also have ON/OFF switch, accelerate/set, deccelerate/set, resume and cancel.
Getting BMW cruise to work with Toyota/Lexus cruise stalk is a whole different story...
...from different car??
From first days of owning a IS200 I really wanted cruise control for it, I looked and even tried to go OEM way adding cruise stalk to steering wheel, but later I found out that wires from stalk don't go anywhere further than steering column, so that didn't work...
Later I was looking at aftermarket cruise kits, but they go around 100+ pounds, have ugly controls, actuators and I think they are nothing near OEM parts quality wise.
In my country (Latvia) older cars still are very popular and especially bmw's, vw's and audi's. so the parts are cheap and widely avelable. I was looking for a cruise control actuator and wanted to programm my own control unit and put it in my car. I even wrote a program that controls actuator with PID algorithm, but never tested it in car. I knew that bmw uses seperate ECU's for almost everything in the car and also for cruise control so I started searching around.. A nice thing also is that older cars (e30, e36) do not have any kind of body or ecu communication bus like CAN or MPX, so that system can work as complete stand-alone unit. (cruise module must be coded if bought brand new from dealer. If the module has been used in a car before, it should work straight away) ahother good thing is that it does not matter if the car was auto or manual, ecu's are the same, there are just minor differences in wiring.
so - I got myself a cruise actuator from a e39 for 15 euros and ECU from 96' e36 auto for another 15 euros, looked up for wiring diagram online and started bench-testing.
For OEM look I bought cruise stalk and steering wheel back cover from IS300 for another 15 euros.
I got cruise control working on my desk using laboratory signal generator as speed input for ecu.
Vehicle speed
Clutch pedal
Brake pedal
are the three things needed for cruise to work
this cruise also have ON/OFF switch, accelerate/set, deccelerate/set, resume and cancel.
Getting BMW cruise to work with Toyota/Lexus cruise stalk is a whole different story...
anyway..
Lexus and BMW cruise stalk use two different ways of telling ecu what the driver wants.
First BMW.
BMW uses stalk that is connected to ECU with 5 wires one is +12 volts and the switch just shorts out those 12 volts to some of the other 4 pins. Thats simple. Easiest way would be controlling the cruise with just few push buttons, one for each function.
this is how cruise stalk from bmw looks like:
![[Image: BMW.jpg]](http://i224.photobucket.com/albums/dd199/dvc_05/BMW.jpg)
As for Toyota...
Those guys are not so simple with their designs so they came up with idea to use just two wires (one is ground) for all cruise control functions. Toyota stalk works as voltage divider. From ECU comes out 12 volts and in cruise switch there are 3 resistors and other wire goes to ground. If some function is being aplied from the cruise stalk, 12 volts from ecu are being pulled down to ground trough some of those 3 resistors. For example if you press on/off, 12 volts are being pulled down to 0, set/coast gives 3 volts, resume/acc gives 6 and so on...
This is how toyota/lexus stalk looks like:
![[Image: Capture.jpg]](http://i224.photobucket.com/albums/dd199/dvc_05/Capture.jpg)
How to control BMW’s ECU with Lexus stalk? I am sure there is a simple way translating diferent voltage levels from Lexus stalk an outputing 12 volt on/off signals using analog circuits, but i choose to use ATmega microcontroller and Arduino board.
I have not checked what is minimal voltage needed for BMW’s ecu to sense some kind of input of switch, but if 5 volts will work, that would be great. Arduino will read output from cruise stalk and translate them to HIGH and LOW states for different pins for bmw ecu.
Now what is left for me is to make wiring more or less pretty and install everything in car. after that, test on jackstands to test all the functions, especially all the safety related and go for a test drive...
hopefully I will make some photos later of the components and installation.
Can posts be edited?
anyway..
Lexus and BMW cruise stalk use two different ways of telling ecu what the driver wants.
First BMW.
BMW uses stalk that is connected to ECU with 5 wires one is +12 volts and the switch just shorts out those 12 volts to some of the other 4 pins. Thats simple. Easiest way would be controlling the cruise with just few push buttons, one for each function.
this is how cruise stalk from bmw looks like:
As for Toyota...
Those guys are not so simple with their designs so they came up with idea to use just two wires (one is ground) for all cruise control functions. Toyota stalk works as voltage divider. From ECU comes out 12 volts and in cruise switch there are 3 resistors and other wire goes to ground. If some function is being aplied from the cruise stalk, 12 volts from ecu are being pulled down to ground trough some of those 3 resistors. For example if you press on/off, 12 volts are being pulled down to 0, set/coast gives 3 volts, resume/acc gives 6 and so on...
This is how toyota/lexus stalk looks like:
How to control BMW’s ECU with Lexus stalk? I am sure there is a simple way translating diferent voltage levels from Lexus stalk an outputing 12 volt on/off signals using analog circuits, but i choose to use ATmega microcontroller and Arduino board.
I have not checked what is minimal voltage needed for BMW’s ecu to sense some kind of input of switch, but if 5 volts will work, that would be great. Arduino will read output from cruise stalk and translate them to HIGH and LOW states for different pins for bmw ecu.
Now what is left for me is to make wiring more or less pretty and install everything in car. after that, test on jackstands to test all the functions, especially all the safety related and go for a test drive...
hopefully I will make some photos later of the components and installation.
This all looks very complicated and is probably a little beyond my understanding. I had always thought that retrofitting cruise to a manual IS200 was not possible!
How will you get the BMW cruise ECU to control the Lexus throttle motor? As isn't that controlled by one of the Lexus ECUs?
![[Image: tempsig2.jpg]](http://i121.photobucket.com/albums/o227/84stoney/tempsig2.jpg)
ad: It was a tough call to make, but the Supercharged IS200 is being retired. ad:If you are a paid member you can edit your posts. If not then you can PM one of the Moderating team and they can edit it for you.
This all looks very complicated and is probably a little beyond my understanding. I had always thought that retrofitting cruise to a manual IS200 was not possible!
How will you get the BMW cruise ECU to control the Lexus throttle motor? As isn't that controlled by one of the Lexus ECUs?
ad: It was a tough call to make, but the Supercharged IS200 is being retired. ad:
main problems were figuring out how to connect one more cable to throttle body for cruise actuator, but I got that going with a zip tie...
other problem was to get the CC to engage - wont go in to small details since it's not that interesting, but the problem was - when I connected BMW's cruise computer to IS200 tachometer signal, Tach drops to zero... solved that by adding optoinsulator for output/input
anyway - cruise works as a charm! just returned from 500km trip around my country and I have not been so relaxed ever before after such a long trip and I averaged 37.6 mpg
OEM stalk works great! On-Off works as it should, accel, decel functions work as they should, but set function is no top, not bottom, but that can be solve by re-programing interface board. also Resume function is not working, yet
Cancel works too
later I will try to connect cruise input to speed sensor and not tach, since now my cruise control works by keeping rpm's steady, but it tends to bounce at low speeds and low engine load.
for those who are worried about safety facotors - cancel function works, and Brake pedal cuts power to actuator. I will add clutch switch later. and there is main power switch in my glove box.
pictures with engine bay later.
It's been a long time since my first post, but finally my CC works!
main problems were figuring out how to connect one more cable to throttle body for cruise actuator, but I got that going with a zip tie...
other problem was to get the CC to engage - wont go in to small details since it's not that interesting, but the problem was - when I connected BMW's cruise computer to IS200 tachometer signal, Tach drops to zero... solved that by adding optoinsulator for output/input
anyway - cruise works as a charm! just returned from 500km trip around my country and I have not been so relaxed ever before after such a long trip and I averaged 37.6 mpg
OEM stalk works great! On-Off works as it should, accel, decel functions work as they should, but set function is no top, not bottom, but that can be solve by re-programing interface board. also Resume function is not working, yet
Cancel works too
later I will try to connect cruise input to speed sensor and not tach, since now my cruise control works by keeping rpm's steady, but it tends to bounce at low speeds and low engine load.
for those who are worried about safety facotors - cancel function works, and Brake pedal cuts power to actuator. I will add clutch switch later. and there is main power switch in my glove box.
pictures with engine bay later.
![[Image: LexuS-Copy.jpg]](http://i65.photobucket.com/albums/h204/Sparkystav/LexuS-Copy.jpg)
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
Sparkystav
04-07-2021, 09:39 AM #8Nice!
Read my thread here: The Evolution of my Turbo Lexus from NA-Supercharged-Twin Turbo-Massive Single
Please leave your comments.
![[Image: 577041B2-7EE2-4B03-BDA8-ACD276DBBA69.jpg]](http://i224.photobucket.com/albums/dd199/dvc_05/577041B2-7EE2-4B03-BDA8-ACD276DBBA69.jpg)
![[Image: 9C24B384-4538-40CF-ABAB-77610ECD5B92.jpg]](http://i224.photobucket.com/albums/dd199/dvc_05/9C24B384-4538-40CF-ABAB-77610ECD5B92.jpg)
![[Image: D3FFCC9A-066E-496C-990F-3EA095162C38.jpg]](http://i224.photobucket.com/albums/dd199/dvc_05/D3FFCC9A-066E-496C-990F-3EA095162C38.jpg)
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