What was found
ON FLIGHT 3349 THE CREW REPORTED THAT AFTER TAKEOFF THE CABIN ALTIMETER DID NOT CHANGE UNTIL 9000 FEET. AFTER THAT IT CHANGED RAPIDLY AT 15000 FEET. IT (CABIN ALT) WAS AT 3300 FEET AND IT WAS SUPPOSE TO BE AT 1300 FEET THE CABIN NEVER PRESSURIZED. THE CREW ELECTED TO RETURN TO DFW. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED CABIN PRESSURE ACQUISITION MODULE IAW EMB135 AMM 21-32-01. THE AIRCRAFT WAS RETURNED TO SERVICE.