Transmission Does Not Shift

Transmission does not shift

Diagnostic Procedure:

1. Input shaft (mainshaft) speed sensor defective

2. Output shaft (countershaft) speed sensor defective

3. Engine output low

Also check for:

- Check for a stored DTC, and check for loose connections.
- Check the speed sensor installation.
- Inspect the sensor O-ring for wear and damage.
- Check for exhaust restrictions.
- Check for intake restrictions.
- Check fuel pressure.