Precor C966 Serivce Manual page 21

4. If the voltage is missing or significantly low, disconnect the speed sensor plug from the lower
PCA. Measure the voltage between pins 1 & 4 of the J2 plug on the lower PCA. If the
voltage is approximately 5 Vdc, replace the speed sensor. If the voltage is missing or
significantly low, replace the lower logic PCA.
5. At this point the speed sensor output is good, but a speed error occurs. There are two
potential causes for this condition. They are upper PCA or lower logic PCA. There are no
good means of troubleshooting these components other than substituting known good
components. Replace only one component at a time. If the component that you replaced
does not correct the problem, replace the original component. Try substituting the lower
logic PCA first then the upper PCA, if necessary.
6. If you have performed all of the above procedures and have been unable to correct the
problem, call Precor Customer Support.
C966 Treadmill
Page 21