Ed (Sawdust) asked me to relay this message because he is unable to get on the internet.
He had an incident today in which his cruise control would not disengage with application of his brakes.
I will not go into a technical discussion of the circuits since I have not looked to see what may have caused this, although Ed apparently has determined it is a relay relating to the ABS. What is important is that you all know your cruise control may not disengage when you apply your brakes.
When you are on cruise, and you apply your brakes, the red brake annunciator light on the dash lights and simultaneouls with that the cruise control disengages. Today Ed had to make a rapid stop and his cruise control did not disengage, nor did the red light on the dash light.
In his case he was unable to stop where he needed to, but fortunately nothing bad happened as a result.
He did indicate that at around 35 miles an hour his cruise did disengage.
I would urge all to be aware that the cruise control circuit like all mechanical things can have failures. This is a case where a failure can have dire consequences. I have experienced a similar event in the past, and ever since then have never relied on my braking to disengage my cruise. I would urge all others to manually disengage the cruise control any time traffic is heavy, any time a stop is anticipated such as when coming to a rest area, or an exit ramp, or when on curvy narrow roads where visibility is limited.
The cruise control can be disengaged using the brake, the square white button, or the cruise control switch. Ed will post more details and I will attempt to verify which likely component failure can cause this problem, but regardless of what causes it, you as a driver should be prepared to manually disengage your cruise control as your primary means rather than relying on braking to do it for you.
At the very least please recognize if the red brake annunciator does not light when the brakes are applied and the cruise is engaged, it means the cruise has likely not disengaged and you may not be able to stop as planned. While you are applying maximum braking effort, your cruise control is applying maximum horsepower in an attempt to maintain the set speed.