Expert: Sean Halliday - 2/8/2008

Question
The speedometer on my son's 2001 honda civic has been intermittent and is now stuck on 120mph. What is the most likley cause? Does this car have a speedometer cable like the cars of my youth?

Answer
There is no cable like the older simpler way.Modern cars have a speed sensor on the transmission which is connected electronically to the clock.If the speed sensor is faulty,the transmission will change abnormally(wrong gear changes,late,early etc),if this isnt happening and it is automatic,it is most likely the clock itself.If your speed sensor goes bad the check engine light will tell you right away as the computor is pretty sensitive.Look at the clock and try  to see if its a bad connection.I havnt heard of this problem with Hondas as theyre usually sound electrically especially the speedo.If your car is a manual,it may be this sensor,did the check engine light come on?