My TCS indicator light comes on and stays on

This indicator has three functions:
It comes on as a reminder that you
have turned off the Traction
Control System.
It flashes when the TCS is
regulating wheel spin.
If it comes on and stays on when
the Traction Control System is on,
it indicates that there is a problem
with the TCS.
This indicator also comes on for a
few seconds when you turn the
ignition switch to ON (II). If it comes
on and stays on at any other time, or
it does not come on when you turn
the ignition switch to ON (II), there
is a problem with the TCS. Take the
vehicle to your dealer to have it
checked. See page
for more
information on the TCS.

I recently purchased a 2005 Z4 (76,000 miles), and I just experienced the same thing (beep, then yellow Brake and Triangle Light (w/exclamation point/semicircle appears on dashboard). It is intermittent. Did you ever find a solution?

Whenever this warning light or any other stays on in the dash it is indicating that the systems control module (or the system sensor in the case of lights like low oil pressure, door open indicators etc.) has detected a fault, it then disables the system (this applies to ABS,TCS, TCM, SRS and BCM faults and others) as long as the light is on. You must now have the dealer hook up a special electronic diagnostic tool and "scan" the system for the fault code that is stored for the problem(s)

Legend of Abbreviations. ABS Antilock brake system.TCS Traction control system, TCM Transmission control module, SRS Supplemental restraint system, BCM Body control module

A yellow explanation point symbol on the dashboard typically applies to the Tire Pressure Monitoring system. A thick ! inside a half drawn flat tire symbol to be complete and comes in yellow color when lit. Under normal vehicle set-up, if this indicator stays lit after the power-on selftest, you need to check your tires for any uneven pressures and adjust their pressures to correct specifications. Okay? : )

A red exclamation point inside a circle when lit indicates your parking brake is on, or your brake fluid level is low.

I suggest that you get the instructions manual, you will find what the icon indicates there... you can also visit a local dealership and have a few chat with the mechanic. I'm sure they will not charge you for a very basic question.

I have a yellow triangle with a ? on my dash what does this mean

The TCS (Traction Control System) indicator comes on or flashes under the following conditions:

When you turn the ignition switch
to ON (II).

When you manually turn off the
TCS.

It flashes when the TCS is
regulating wheelspin.

If the system's diagnostics senses
a problem in the TCS, the indicator
will come on and stay on.

If the brakes overheat, the
indicator will come on.

If the TCS indicator comes on and stays on for more than 10 minutes while driving, pull to the side of the road when it is safe and turn off the engine. Reset the system by restarting the engine, and watch the TCS indicator. If the indicator remains on, or comes back on while driving, have the system inspected by your Honda dealer. You can still drive the vehicle without TCS.

This indicator will come on along with the ABS indicator if there is a problem in the anti-lock brake system.
The TCS indicator may occasionally come on for one or two seconds and then go out. This is normal.

Hope this helps you figure it out.

You are talking about the VSA activation indicator (triangle with exclamation point in the middle):
This indicator has three functions:

It comes on as a reminder that you have turned off the vehicle stability assist (VSA) system.

It flashes when VSA is active.

It comes on along with the VSA system indicator (the rectangle with VSA in it) if there is a problem with the VSA system.

This indicator normally comes on for a few seconds when you turn the ignition switch to the ON (II) position, and when the ignition switch is turned to the START (III) position.

Hope this helps you understand the problem.

the exclamation point inside a triangle is the VSA activation indicator or Vehicle Stability Assist system indicator. If the indicator stays on, have the VSA checked at the dealer.

may have a faulty brake switch check switch!!