Saab 9000's with Traction Control System (TCS) use the following method to determine when to shut off TCS:
TCS and ABS (Anti-lock Brake System) share the wheel speed sensors
TCS insures that one wheel doesn't rotate faster than the others.
ABS insures that one wheel doesn't rotate slower than the others.
TCS is therefore always operational until ABS is asked for, via the brake peddle.
So in order to disable the TCS, we need the TCS Controller to think that we are stepping on the brakes.
Materials Needed:
A Switch
some wire
Diode
Test light
Install your switch wherever you like in the car
Connect power from a switched power source (easily found using a test light)
Locate the Brake-Light-Signal wire to the TCS ECU (TCS ECU located under the driver seat)
From the information I've found, Pin 36 on the TCS ECU is the brake switch input
Once your brake switch signal wire is located, splice into it, and connect to the other side of your switch
Add a diode between your splice and the rest of the brake light circuit, this ensures that the brake lights will not be illuminated when the switch is activated.
Now when driving, if you activate your new switch, the TCS Controller will think that the brakes are being activated and disable the TCS!
(Original information found from forums on SaabLink and SaabCentral - If you have more information or find an error with this theory, please let me know!)
TCS and ABS (Anti-lock Brake System) share the wheel speed sensors
TCS insures that one wheel doesn't rotate faster than the others.
ABS insures that one wheel doesn't rotate slower than the others.
TCS is therefore always operational until ABS is asked for, via the brake peddle.
So in order to disable the TCS, we need the TCS Controller to think that we are stepping on the brakes.
Materials Needed:
A Switch
some wire
Diode
Test light
Install your switch wherever you like in the car
Connect power from a switched power source (easily found using a test light)
Locate the Brake-Light-Signal wire to the TCS ECU (TCS ECU located under the driver seat)
From the information I've found, Pin 36 on the TCS ECU is the brake switch input
Once your brake switch signal wire is located, splice into it, and connect to the other side of your switch
Add a diode between your splice and the rest of the brake light circuit, this ensures that the brake lights will not be illuminated when the switch is activated.
Now when driving, if you activate your new switch, the TCS Controller will think that the brakes are being activated and disable the TCS!
(Original information found from forums on SaabLink and SaabCentral - If you have more information or find an error with this theory, please let me know!)
I also managed to find the .pdf from Saab on installing the switch, this is meant for Saab mechanics, and therefore reads as such - using the actual Saab 'TCS' switch which fits in the standard button slots on the dash.
tcs+switch.pdf |