Just purchased a 1994 Honda EX 2.2 L engine; 195,000 miles. New transmission in March 2010. D4 light comes on with a Code 9 Countershaft speed sensor.
CEL not on. Car running great. RPM and speedometer working perfectly.

I see in this forum where this could be a "cleaning" issue or a "replacement" issue. In looking at parts on line, this part is fairly cheap.

1. Should I just have it replaced?
2. Is there a correlation to the VSS (do they usually fail at the same time so I should I replace that too?)
3. I'm having surgery tomorrow and will not be able to get it taken care of for a little while. If I drive it with the D4 flashing for short distances (10 miles) to dr appts, will I risk damaging the engine?

Thanks for any help you can offer.
Nancy

 

Check to see if the sensor is unplugged or has a loose/dirty connection.

The countershaft speed sensor doesn't control the speedometer, the vehicle speed sensor does that. The countershaft speed sensor sends a signal to the transmission computer.

If the car is running and shifting properly, then you will be ok until you fix it. The transmission computer is likely ignoring that signal, since it is likely out of range.

 

It may be repairable, and worth a try,...if the sensor is easy to access. If difficult, get a new sensor and replace. Open the sensor cavity, clean, and relube lightly.

good luck