Lexus IS Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1 (Edited)
I found some old posts with some info, but nothing 100% condensed or any working pics. Most of the info was from posts by the user "Gery", so hats off to him. (http://my.is/forums/f88/vsc-disable-344712/) Neither myself nor Gery are responsible for what you do with this info!

Tools needed:
wire cutter
wire crimps
16-22awg wire, 24-48" long
SPST switch (dpdp, spdt, etc all work)
*OR* tiny flathead screwdriver


The theory here is to disable power to the steering angle sensor. If you simply remove the VSC/TRAC fuse, you also lose ABS. This method keeps ABS enabled, which is recommended for all but pro racers on a track.

For a LHD IS300, you will first remove the kick panel left of the pedals. In the front is a plastic screw, in the rear are 2 snap-tabs and another that connects to the door sill trim. Remove all and you have access to everything you need.

Next locate the "1A" connector. The interior fuse box has several connectors plugged into it, the 1A is the third up on the left side. Remove it by pressing it's lock pin and pulling.




Once removed and facing you (wires away from you, see pic below), locate the #4 wire. It will be on the upper-right side of the connector face colored black/red. You can either cut this and connect to your switch, or de-pin it. To de-pin you stick the small flathead under the pin then push in & up on the screwdreiver while pulling the wire. It takes more effort than you'd think.



If the wire is disconnected or the switch is off, VSC and TRAC will be disabled while ABS is enabled. VSC/TRAC lights will be on, ABS will not. If you attempt a rear-wheel powerslide (drifting), you will have zero assist SO BE CAREFUL. The lights will not blink nor will you hear the chime.



To enable the VSC/TRAC simply reconnect that wire and cycle ignition power. If you want to enable it while driving, you need to add a 2nd switch to the traction computer's power wire. I have not tried this but the user "Gery" posted the pic below showing how. You can see on the right the switch for wire #4 on the 1A connector. The reset switch is the one in the middle, wire #4 on the 1L connector.



If you look at the fusebox picture, it is the connector on the bottom-left. Do not confuse that with the floating connector on the side of the fusebox. When pulled out and the pins facing you, #4 wire will be on the bottom-left. Use a N/C switch (normally closed or "on"; momentary switch can be used) to open & close that connection. Before you cycle that power switch you must reconnect the VSC/TRAC connection.




Just a note for Safety: please avoid driving crazy on public roads. If you aren't experienced with the road or a rwd drift, you can EASILY loose control. It is entirely possible to flip your car if you're going sideways into a shoulder/curb/etc, and w/o a seatbelt you may lose more than your car.

If you are willing to accept any accidents, start on a road that is flat, dry, free of: gravel, sand, dust, curbs, other drivers, pedestrians, animals, ditches, and houses. Keep w/in the speed limits and obey all traffic signs & lines.

Legality: as far as I know these cars were not legally mandated to have VSC, and I don't know of any laws that prohibit disabling VSC. Please be check local laws, as that may change after this is posted.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #5
The TRAC OFF button only disables traction control, not stability control, aka Vehicle Skid Control or VSC. When the wheels spin faster than the front, only traction control intervenes. When the back end of the car is rotating differently from where the front wheels would indicate (steering angle vs yaw rate), VSC kicks in.

If your TRAC OFF button lets you do donuts, then you don't have VSC. 2001 did not have VSC and for 02-05 it was optional with automatics. My car is an auto, since I got it for a steal from my sister.
 

·
Registered
Joined
·
5,270 Posts
This is pretty neat.

I disconnected the 4 wires between the Trac ECU and the main ECU (just unplugged them on the main ECU side, heat shrinked and put them aside). I still have ABS but the ECU doesn't pull back throttle because it's not seeing the input from the track ECU.

The 01's have an issue where the trac prevents proper acceleration.
 

·
Registered
Joined
·
671 Posts
@Hydrocarbon82

I appreciate this write-up. I push the Trac button every single time I get in the car and it's become second nature. The only time I get annoyed is when I try and spin the tires and forget to have pushed the trac button and Cannot do said spinning of tires.. However, when it rains here in CA for the first couple hours after a long dry spell the roads are ridiculously dangerous and "de-pinning" would be quite a bit of trouble.
A small toggle switch seems appropriate to wire in for this and can be used easily between seasons. Again, I appreciate your write up and I will try soon and post my feedback. Thank you
 

·
Registered
Joined
·
66 Posts
This is pretty neat.

I disconnected the 4 wires between the Trac ECU and the main ECU (just unplugged them on the main ECU side, heat shrinked and put them aside). I still have ABS but the ECU doesn't pull back throttle because it's not seeing the input from the track ECU.

The 01's have an issue where the trac prevents proper acceleration.
I have an 01 auto, my trac light flashes constantly. Is this affecting the engine? and also, any ideas on how to fix it?

Im planning on swapping next year, but I don't mind doing easy fixes on this motor. thanks guys
 

·
Moderator
Joined
·
3,275 Posts
I have an 01 auto, my trac light flashes constantly. Is this affecting the engine? and also, any ideas on how to fix it?

Im planning on swapping next year, but I don't mind doing easy fixes on this motor. thanks guys
Yes it has an effect. Get it scanned and see what codes come up.
 
1 - 14 of 14 Posts
Top