HEADS UP DISPLAY. A DIGITAL PROJECTED DISPLAY ON INSIDE OF WINDSHIELD CONTAINING VEHICLE INFO SUCH AS SPEED, ENGINE TEMP, RPM, ETC. FOR DRIVER INFOR...
I can't even begin to tell you how many false statements based on suppostion our friend awschucks has made on that thread.
Quote:
awshucks wrote on the CF:
In response to one discussion item above, locking up a wheel is a lot different than the ABS system applying the brakes to the right rear. A 'locked' up wheel has a very low coficient of friction making it fairly easy to steer the car with one wheel locked. In the case of ABS applied brakes you will get a car that is almost impossible to control with the other wheels as they all have about the same friction. As an example, ABS systems can stop a car faster than most drivers. Computer brakes keep the wheel turning just above the point where it will skid.
Second response: Both C5 and C6 share the some design.
The most likely cause of a problem would be an intermittent signal to the AHC based on a bump or other vibration. You should see a warning on the DIC about servicing the Active Handling Computer if you have a problem with this connector.
I have been reading other forum discussions about seeing this warning and they are suggesting the solution is wiggling the connector. This is not going to fix the problem and may be creating a potential problem with the handling of the car that can cause the brakes to self apply on selected wheels.
If you see the warning and have the connector serviced, I'm suggesting that you or the tech use white lithium lube on the connector. You should also make a determined effort to keep the connector from flexing when the steering wheel is moved in and out.
You might try to replace the connector, but that brings up a full can of worms. Should I use the existing connector design or use something better? As I said earlier, solder is the best, but there are better connectors that could be used if you want to fix this once and for all.
I think every description of how AH and ABS work that he mentions above is wrong.
I'll have more time later, but let me address the initial comment that a bad SAS, or steering angle sensor, will send your car into the ditch. The SAS supplies its values on the vehicle CAN communication bus. Very few things are hard-wired anymore. If the SAS failed, AND its own internal diagnostics didn't catch it, or if it had an intermittant connection, it would simply NOT be sending steering wheel angle to the rest of the vehicle. The ESP module, no longer receiving steering angle, would shut down active handling and light the warning lamp.
But let's suspend disbelief for a minute further and say that instead of sending no signal, the SAS sends out an erroneous signal to the vehicle, and thus to the ESP module. The third degree of error checking would then come into play: The car would take the "supposed" steering angle along with the vehicle speed and calculate the expected yaw. This would then be compared to the amount of yaw measured by the yaw sensor. Noting that they were way off, the system would assume one of the sensors was bad and shut down AH.
In this case, ABS and Traction control still work fine (they require no steering angle value or yaw sensors) but the ESP module would disable active handling and light the warning light.
There is no case where the car will activate a brake to help you with a fake steering input and drive you into the ditch. This is an obscene example of someone with a voice on the internet propagating fear for attention.
Also, good luck getting your DelCity "off the shelf" connectors to handle the 100,000 miles and 10 years of vibration and freezing temperatures that your GM specified connector is rated for. BTW, most (dare I say all?) safety critical connectors are gold plating over tin or nickel. With a minimum gold thickness. They do a pretty good job of resisting corrosion.
