VSC/TRAC light stays on (2010 Hatchback - Automatic)

[mxa77]

I recently installed the following with the help and information I got from different sources in this great YarisWorld forum:

- Fog lamps with OEM headlight switch
- Cruise Control (OEM control )
- Prius variable wiper switch (replaced original)
- Heated Seats (Seat warmers and Glazzios seat covers from microimageonline)
- After market Navigation System that replaced the factory radio as plug and play (no wiring modifications)

After I got everything working and got all excited, I realized somewhere in the process the VCS/TRAC light has decided to come on and stay on.

The car has been sitting in the garage for almost a month while I've been doing this work a little bit at a time, so it hasn't been driven.

Now, I've wondering what caused the VSC / TRAC light to come on and stay on. After doing some research I found out the 2010 hatchbacks had the VSC / TRAC feature as standard (didn't even know I had it), but there's no switch to turn it on/off.

So, my question is what could have caused this to happen. I checked all the wiring and everything looks good and operational.

Any help to figure out how to troubleshoot would be really appreciated.

Also, is there any simple way to add a switch for the VSC/TRAC?

Thanks everyone!

[CTScott]

You can read the DTCs (diagnostic trouble codes) from the ABS/VSC system, by jumping 3 pins on the diagnostic connector (next to the hood release lever) and watching the flashing pattern of the VSC lights:

ABS DTC Check.jpg

With the ignition on, connect the three pins shown above together.

Count the number of blinks of the ABS warning and SLIP indicator lights.

• When the system is operating correctly, each light will blink continuously in a pattern of 0.25 seconds on, then 0.25 seconds off.
• When one DTC is output, each lamp will output the same code at 4 second intervals. (For example, Code 21 would be output as 2 flashes, a 1.5-second pause, and then 1 flash)
• When 2 or more DTCs are output, each lamp will output a different code at 2.5-second intervals, and when all codes have been output, there will be a 4-second pause and the sequence will repeat.
• When multiple codes are set, they are output in order starting with the lowest DTC number.

After performing the check, disconnect SST from terminals TS and CG, and TC and CG of the DLC3 and turn the ignition switch off and then back on again.

[jRoss]

My trac light won't come on some times...what's up with that?

[CTScott]

The lights either staying on or not coming on both indicate the same thing - Problems with the system:

TRAC OFF indicator abnormal (Remains on):
TRAC OFF indicator light circuit
Brake actuator assembly (Skid control ECU)

TRAC OFF indicator abnormal (Does not come on)
TRAC OFF indicator light circuit
Brake actuator assembly (Skid control ECU)

VSC OFF indicator abnormal (Remains on)
VSC OFF indicator light circuit
Brake actuator assembly (skid control ECU)

VSC OFF indicator abnormal (Does not come on)
VSC OFF indicator light circuit
Brake actuator assembly (skid control ECU)

SLIP indicator light abnormal (Remains on)
SLIP indicator light circuit
Brake actuator assembly (skid control ECU)

SLIP indicator light abnormal (Does not come on)
SLIP indicator light circuit
Brake actuator assembly (skid control ECU)

[mxa77]

OK. Last night I opened up the steering shroud to check the wiring and all the connection again. I found out a connector (long skinny one with few wires) that was located under the steering column (behind the yellow connector) was still unplugged from when I removed the steering wheel assembly to install the OEM foglight switch/Wiper variable switch and cruise control.
I plugged the connector in and the light went off.

I like the design on these cars and how modular everything seems to work on them. I'm sure glad it wasn't anything else, and thanks for the invaluable information that CTScott provided. I'm sure it will come in handy in the future.

Thanks