CAM Sensor Check

My daughter ownes a 2003 Dodge Neon 4cyl. Soc not HO. On Monday night the Check Engine Light goes on but with no appearant problems. Tuesday morning the car stalls at a red light (1/4 tank gas) but Check engine light is now out. Service diagnosis tells her to check Cam sensor/wiring harness/connectors, and she is also told that the timing is off. From reading other letters to you I note that timing belt is due change around 64,000 miles-she has 70,000 on the car. Is there a test that I can do with a multimeter to see if the Cam sensor is sending the correct signal at home and if so what are the parameters for proper operation. Since the incendent on Tuesday she has has no further problems but is hesitant to dirve the car. Is there a procedure for me to check trouble codes without buying a scanner?