it could have a bad speed sensor
tranny problems
To check the hold light blinking of a Mazda Protege, take off the plastic over the shifter tube or bar. Then take off the console below it and look at the wires that come up from the hollow center of the tube. The edge of the shifter tube may have cut through the wire insulation.
The speedometer cable (which runs from the transmission to the dashboard) has snapped. This is a two-piece cable, and the one-piece cable in later Proteges will not work. I had the transmission replaced, and the cable could never be fit in properly. This is a mechanical speedometer, so you would have to change the entire speedometer part of the instrument panel to use a magnetic/electronic speedometer.
reset it.
Fuse panel.
Sorry guys but from experance with 2.0 DOHC 16 valve that blinking hold light means your transmission is about to stop working with mine it started blinking and with in a half an hour of driven the tranny breaks and you loose all gears and the only way to fix is a new transmission or to have it completely rebuilt and a new one from Mazda is about $2100
Have the trouble codes retrieved with an OBDII scanner to identify the problem areas before you start spending on repairs that might not be the cause of the problem(s).
My knee-jerk answer would be a TCM (Transmission Control Module) problem, but have a shop hook up a scan tool and they can tell you what is wrong.
Above the brake pedal,its black plastic.
This indicates a problem with the transmission. Take it to a professional.
The HOLD light means you have an electrical problem with your transmission. See your mechanic ASAP.
It is run off of the same fuse as the engine computer.