Why is by ACS TCB off warning light coming on on my dash board?

There is no warning light for catalytic converter heating uo. Brake light usually is a exclamation mark inside a circle inside parentheses. What you are describing sounds more like a temperature warning light for the cooling system.

I think you mean TBC,,..
Trailer Brake Control ...

The warning lights should be listed in your owners manual. It could be a warning for one of the gauges, or engine/transmission problems.
They are more common on Toyota Prius.

you have to hold the toggle until the light comes on, on the dash.

There are few help links provided to resolve this issue of dash board light not working.Click the link below to go through its procedure:-----Dash board lights not working? http://repairhelpcenter.blogspot.in/2012/02/dash-board-lights-not-working-on-gmc.html
----------- light in the dash blinks? http://repairhelpcenter.blogspot.com/2012/01/overdrive-light-in-dash-blinks.html
-----------Orange O/D warning light flashing on dash? http://repairhelpcenter.blogspot.com/2012/01/orange-od-warning-light-flashing-on.html
---------gauge on the dash quit working on? http://technoanswers.blogspot.com/2012/01/temperature-gauge-on-dash-quit-working.html---------No 4x4 light on dash? http://repairhelpcenter.blogspot.com/2011/12/no-4x4-light-on-dash.html
----------Digital Dash Display not working? http://schematicsdiagram.blogspot.com/2011/12/cadillac-seville-digital-dash-display.html
---------warning on dash and alarm sounds? http://schematicsdiagram.blogspot.com/2011/12/chevrolet-tahoe-hood-open-warning-on.html
---------Light Stays On dash of car? http://schematicsdiagram.blogspot.com/2011/06/brake-indicator-light-stays-on-dash-of.html
----------The ABS and Traction Control Lights stays ON dash of car? http://schematicsdiagram.blogspot.com/2011/06/abs-and-traction-control-lights-stays.html
----------warning lights remains steady on dash? http://schematicsdiagram.blogspot.com/2011/12/abs-brake-warning-lights-remains-steady.html
---------light bulb under dash replacement?

http://schematicsdiagram.blogspot.com/2011/12/heating-knob-light-bulb-under-dash.html

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Parking lights, tail lights and dash lights not working? http://technoanswers.blogspot.com/2012/01/parking-lightstail-lights-and-dash.html

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How to replace Instrument panel and dashboard?

http://repairhelpcenter.blogspot.in/2012/02/how-to-replace-instrument-panel-and.html

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Tail lights and dash light fuse keeps blowing? http://technoanswers.blogspot.in/2012/02/tail-lights-and-dash-light-fuse-keeps.html

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This will help.

Thanks.

Here are the warning light meanings:
Hope this helps

Check your brake fluid level first. If it is fine then you probably have a bad abs brake sensor.

abs warning light stays on jaguar s type 2001 can you help

This warning light indicates a problem with the rear lights (Brake lights, Reverse lights, Number plate light)... Normally it is set off by a bulb that needs to be replaced but it has been documented that using incorrect Watt rated bulbs can also trigger the warning light. It has also been noticed that faulty wiring may trigger the it too.

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