Oldsmobile/Buick Repair: 1994 OLDS 88 Royale LS, scan tool, obd2

Question
Why do I get an error message on my mileage OD while driving? It clears out once it is off for a few hours, then it works for a few miles and then error appears again.What can I do?

Answer
HI JAMES,THIS SOUNDS TO ME LIKE THE SPEED SENSOR IS GOING BAD ON THE TRANSAXLE..THIS SENSORS KNOWS HOW FAST THE CAR IS GOING AND SENDS A SIGNAL TO THE ODOMETER..DO YOU FEEL THE SPEED IS CORRECT ??? YOU COULD GET THIS CAR SCANNED AND SEE IF THERE ARE ANY TROUBLE CODES IN THE SYSTEM..ALSO REMEMBER WHEN HAVING THIS SCANNED THIS WILL BE PRE OBD2..SO MANY SHOPS MAY NOT HAVE THE SCAN TOOL FOR THIS OLDER CAR...IF THEY CAN SCAN THE COMPUTER THERE [SHOULD[]MAYBE] BE CODE IN IT FOR THIS FAULT.IF THERE ARE NO FAULT CODES IN THE SYSTEM AND THE SPEEDO WORKS GOOD. THEN MORE THEN LIKELY THE PRINTED CIRCUIT IN THE DASH IS GOING BAD....LET ME KNOW HOW IT GOES AND IF YOU NEED MORE INFO GET BACK TO ME...GOOD LUCK TOM...