ya know what, same thing happens to my car TOO.
after driving at a reasonable pace on the highway (about 80-90mph) it comes on and won't shut off. came back from oklahoma, and a freind of mine drove it (while i was sleeping, didn't bother to wake me up) all the way through missouri with the od off light flashing. now it does it all the time, and the codes came up on a snap on scanner as "transmission overheat" and "torque converter lockup failure", not to mention my engine problems: "OBDII system checks incomplete" but driving it how it says in manual doesn't help, and "lean mixure, bank 1", probly one of the oxygen sensors.
but yes, i feel your pain........ i'm not liking the cd4e's