Q: Speedometer jumps car moves slow

If your speedometer needle or gauge is jumping up and down while the vehicle is moving at a slower speed, two possible issues may have occurred. Either the whole instrument cluster has failed at some point preventing the speedometer from working properly or the sensor on the transmission that reads vehicle speed may be faulty.

I would recommend having a qualified professional take a look at your vehicle to verify this diagnosis. I would recommend starting with the transmission sensor as it is the most common cause and the easiest to access. The technician would run a test on the sensor to determine if it is functioning properly and based on the results the technician would replace the transmission sensor.

If the sensor is not the cause of the issue, many parts of the dashboard will need to be removed in order to remove the instrument cluster. Once the instrument cluster has been removed, the technician can bench test the instrument cluster to determine if the cluster is working properly. If the cluster turns out to be faulty, a new cluster would be installed in the vehicle to resolve the issues you are currently having.

If you need some help with fixing this issue, consider YourMechanic, as one of our certified technicians can diagnose the issue with your speedometer and loss of power firsthand.