O.K. got rid of code 15 and 33 (new coolant temp sensor seems to have solved this) Thanks to all for replies. Now I am getting only code 34 Stepper Motor. Truck had codes 15-33-34 a few weeks back. What is stepper motors function? Where is it located? How do I check it? Thanks Dan

The stepper moves the optical pickup advanced or retarded on the data disk. If the punp is too far out of range the stepper won't beable to find it's range and it throws the code.

My 95's code 34 went away with a new stepper motor, but hey, the dealer may have just timed it wrong and didn't say anything to me. You wouldn't think they would have but you never know.