After a couple of hours of 50-60 mph winding road with use of hi and low jake and manual downshift we were stopped in Traffic. The Check Eng. lite came on steady and the Stop Eng. lite blinked on and off a couple of times. All eng gage readings in the normal range, oil level and coolant levels were checked 'good' prior to the drive. OAT ranged from 89 to 76 degrees.

To turn off the Check Eng. lite I shut down and restarted the engine. Drove without any warning lites for about 30 minutes and while stopped for traffic again, the same occured again.

Any Ideas folks? Thanks!!