No it is not adjustable.
You need to take it to a repair and have then scan the system for codes and diagnosis it. It could be as simple as dirt on a sensor.
Yes, but a unit without a sensor will not provide a sensor signal.
If the speedometer and abs light are not working then you have a speed sensor problem. If the speedometer or odometer are not working then you will need to take it to the dealership and have them send it off for repair.
The VSS speed sensor in an 04 Impala is located on the transmission case or the rear axle of the vehicle. However, on some Impala's it can be located inside the ABS system.
On a 2004 Chevy Impala, the traction control sensor is located in the ABS pump module. On the driver side of the car, the sensor is located at the left center of the engine compartment with black wires hanging from it.
usually a bad wheel sensor, get it checked out.
There are numerous things that can set an ABS light. You need to have it scanned for codes and have it diagnosed. If the speedometer is not working then the speed sensor in the transmission will cause it.
Take it to a mechanic and throw money at it.
Probably wheel speed sensor failure (in the wheel bearing assembly).
fix the problem first or it will just come back on, usually a bad front wheel sensor.
usually it means that something is wrong with it, but you'll probably have to look in the owner's manual
Bring to a shop that has an ABS scanner to determine problem with ABS light Sounds like rotors may be out of round causing shimmy need to be resurfaced or replaced