The speedometer and the tach went all kablooey on my Accord

Hello

I have a 2004 Accord w/automatic trans. My dogs and I were driving home to Boston when my speedometer went all kablooey. The needle suddenly dropped from 65 down to 0, then bounced up again. Then dropped back down and stayed there. Then it came back up. Meanwhile, the little light that tells you which gear you?re in (drive) started blinking on and off. Then the ?malfunction indicator? light came on. The revs were way up to almost 4 while I kept driving at about 60 mph in the slow lane. I couldn’t hear the engine with all the highway noise but it felt rather like I was driving in second gear (very jerky and reved.) The dogs and I made it home to Boston safely but something is clearly amiss! I?ve only lived here 3 months and I don?t even have a mechanic yet! If you can I offer any advice I would appreciate it!

Francesca

The problem might be with the Vehicle Speed Sensor.

This sensor informs the computer the vehicle speed so the proper gear shifts can occur. This sensor also drives the vehicle’s speedometer. If the signal is lost from this sensor the speedometer will stop working, and since the computer doesn’t know how fast the vehicle is traveling it will put the transmission into a limp mode. This causes the transmission to raise the hydraulic pressure causing the jerking shifts and it won’t shift past second gear.

See if there’s an auto parts store such as an AutoZone in your area that will connect a scanner to the vehicle for free, and see if a Vehicle Speed Sensor code comes up.

Tester

oh thank you . . . do places like Autozone do this kind of thing for people? Or should I just find a mechanic someplace?

Some AutoZone stores will pull the codes from your computer for free. But you have remember, even if you get the code, the mechanic is still going to want to hook up their scanner to confirm that it’s the problem. So you’ll probably be charged a diagnostic fee.

Tester

Hello again
Well you were very nice to write and so I figured I’d give you the update. I took the car in and the mechanic said it was likely the VSS just as you suspected. So left the car with them and they said they took it on test drives and it’s running perfectly fine and the computer reading is perfectly fine. He said he knew I wasn’t making it up, but that sometime “these things happen” and that I should just take it in again if it does it again, and that I should “only drive it locally.” I can’t blame the guy for not reproducing the problem, but sheeesh . . . I’m sort of grounded until the silly car gives me a repeat performance.

Well, if the mechanic was worth his salt he should connected a scanner to the vehicle and looked up the history codes. If there was a problem with VSS it would have showed the code there.

Tester

Such is life with these modern cars. There have been a few posts lately about electronic problems that happen, but never for the mechanic. And, unless it acts up for the mechanic, he cannot determine the proper fault.