Repair Topics / Speedometer-1 / Speedometer-2

MORE: Speedometer questions

Vehicle Speedometer Questions

Question: 1998 Ford Taurus SHO mileage: 140,000. The speedometer will not work and the transmission will not shift. We have been told it is many, many things and nothing so far has worked. They told us it was because of the anti-thief device then because of the fuses and then they said there may be a wire broken in the wiring harness. Do you have any advice that may help?

Answer: You may have a faulty vehicle speed sensor in the transmission. This sensor signals the computer to shift the transmission and also drives the speedometer.

Question: 1999 Honda Civic EX, mileage: 144,000. Speedometer problem. Car was wrecked on the front driver's side. Engine and transmission removed to replace part of framing. When removed, coolant got into the Speed sensor and Electrical plug connected to it. When car was finished, everything worked fine. Then about a week later, the speedometer dropped to zero for long periods of time and finally quit. The speed sensor was replaced and everything worked fine for six months and then all of sudden it started jumping around. It will drop to zero and will jump to 100 mph. Sometimes the Needle will jump as soon as the car is started. I have since replaced the sensor as well as spliced in a new plug elimination those two areas. What do you think the problem is? What is the best way to trouble shoot this without pay Honda a fortune or just replacing everything?

Answer:   Because you replaced the speed sensor and are still experiencing the problem, we suspect that you have a faulty speedometer cluster.

Question: 2000 Chevrolet Silverado 1500 mileage: 94,000. How can I tell if my speedometer had possibly been disconnected before I bought this truck?

Answer:   You cannot drive this make and model vehicle with the speedometer disconnected because the transmission will not shift out of low gear and it will cause a "service engine soon light".

Question: 1999 Chevrolet Cavalier, miles: 98,200. The speedo dosn't work, they told me to replace the cable. Went to buy one. The mechanic there said it should be a sensor. Possibly just corroded. LOOKED and LOOKED. Just can't seem to find the dumb thing. Found something. (This will be interesting to explain) here it goes... I found a wire it connects to a big round cylinder. Located closest to the windshield (under the hood) on the left hand side. (It's located way up in the hood, I mean right next to the windshield, not even close to the transmission right behind and to the left of the air filter) Now, the cylinder has 2 wires going into it. 1 is black colored, that one looks really clean and inserts into the cylinder. 2 pink colored, simply has a clip, and slips onto a L bracket (pretty small). Went ahead and unscrewed the pink one. Cleaned completely. No more corrosion. Reconnected. Wow! The speedometer wants to work. Where can I find were the pink wire goes. It should go to the transmission. But where? Can I get to it without dropping anything off? Like the cover of the transmission? I really need help. (Can you tell)? I know you two get a lot of goofy questions. This will be one of the best. Using cylinder as a description. Thanks guys!

Answer:   We feel your problem is with the vehicle speed sensor. It should be located on the transmission tucked underneath the motor very close to the passenger side axle. If the wires have come off or are corroded, this could be your problem. If the wires and connectors look okay, then most likely, the sensor is bad.

Question: 1999 Honda Accord mileage: 80,000. My speedometer started failing some time ago. It would jump to 20 mph and shake a little around it when I drive slow, then just stay there when I speed up. It recovers sometimes and shows the right speed. If I kick the daily miles reset button a few times, it starts working occasionally. It also often kicks in when I drive longer on a highway. Is this the speedometer, the wiring or the speed sensor? How to fix it?

Answer:  Sounds like you have a weak signal generator for the speedometer. Replacing it should fix your problem.

Question: 2002 Chevrolet S10 Blazer mileage: 92,000 We were driving on the interstate last week after an ice storm and had 4-wheel drive engaged. We hit a patch of ice as we were accelerating to avoid a motorist who lost control and all wheels slipped and spun causing the speedometer to "bounce." After all the excitement the gauges were "bouncing" and we noticed the odometer had approximately 20,000 more miles on it than it had. Why would this have happened? Isn't the odometer tied into the revolutions of the drive shaft? Our dealer said it was impossible and we even had an invoice where we had our Blazer serviced a week prior but with 20,000 less miles.

Answer:   It sounds like your computer had a glitch, it happens from time to time, not very common.

Question: 1994 Ford Windstar mileage: 92,000. Recently we had another new transmission replaced (the second one in less than a year and the warranty had just went out on the first one) in our van. They also replaced the speedometer cable (after reaching 40 mph it was swinging back and forth between 40-65 mph making it difficult to get an accurate speed). Well, that didn't work. But my question is do we need to have the speedometer head replaced/rebuilt and does that affect the transmission if we don't get it done right away?

Answer: The speedometer problem may be caused by the speedometer cable binding or the speedometer head itself. If it is the cable, other than the uneven speed reading, it should cause no problems. If it is the head, it may break the new cable.

Question: 1997 Ford Windstar mileage: 113,000. A few months ago digital speedometer became so dim that it is almost unreadable. Lately all the digital displays followed suite, including the tach, fuel gauge, oil press, etc. Checked all fuses, not the problem. All the displays are working, they just don't have any brightness to them, its like they lost there power.

Answer:   Unless you have inadvertently turned your dimmer switch, it sounds like the dash light bulbs behind the speedometer and other gauges are burned out and need replacing.

Question: 1998 Dodge Dakota mileage: 107,000. Speedometer works (non-digital), cruise control works, but odometer remains stuck at 107,000 miles and trip counter doesn't work. The speedometer cable connection is good at the transmission. Are there two connections at the instrument cluster one for the speedometer and another for the odometer and trip counter? Paul

Answer:  No, there is only one speedometer connection on the back of the instrument cluster. You probably have a stripped gear inside the speedometer head causing the odometer to stop working..

Question: 1997 Pontiac Grand Am mileage: 108,000. Problems on an Pontiac Grand Am 2.5 liter manual 5-speed transmission, with a transaxle-mounted electronic SPEED SENSOR. The speed sensor stopped working months ago, and I have since replaced it AND the ECM. It's still not working. As a test, I attached the VSS harness to the OLD sensor, and rotated it with a drill. The speedometer worked, so I know it's not the VSS itself or its related electronics. As I probe the VSS port with a finger, I find no gear to spin the sensor, at least that I can recognize. I feel one gear that has severely slanted teeth off to the side of the port, but it would spin in a direction along the length of the shaft. It seems that there should be a gear between it and the VSS shaft. Here's the curious thing.... a week or so ago (before replacing the VSS and ECM), the speedometer briefly kicked in. Is it possible that I dislodged a gear from its seat while removing the old VSS, and it fell into the transaxle housing?

Answer:   Remove the part of the transmission housing that the sensor plugs in to. You probably have a broken gear or it has slipped on the shaft.

Question: 1999 BMW 740i mileage: 130,000. My speedometer doesn't work at times. How can I fix it?

Answer: Try replacing the vehicle speed sensor in the transmission.

Question: 1999 Plymouth Voyager mileage: 100,000.  My speedometer decides at times to not work at all- when this occurs, the odometer does not turn either. A garage found speedometer cable for me but I don't think that my 1992 even has a cable for this- Haynes repair manual does not help much- can’t find it - and there isn't any good drawings for showing where it is.   How can I tell if it is a cable or a speed sensor or something else since it affects the odometer also?  Tired of guessing how fast I'm going which is usually slower than anyone on the road to be safe than sorry and get a ticket.

Answer: You are correct, your van does not have a speedometer cable; it has a vehicle speed sensor generator that is located in the transmission.  The vehicle speed sensor generates a signal for the speedometer and the odometer.

Question:  1999 Chevrolet 1500 Truck mileage: 135,000.  I always pull the battery and store the truck for MN winters - this time when I got it out I have no speedometer and the computer is in limp mode - nothing above 2nd gear - everything worked when stored for winter - where can I trace the connections for the speed sensor 

Answer: We do not think your problem is the speed sensor for the transmission.  Check all electrical fuses if ok, the ignition switch may be faulty.

Question: 1993 Ford Mustang mileage: 190,000.  My speedometer bounces up and down and I don't get and accurate speed rating. I replaced the plastic little guard in the transmission that turns the speedo cable, in hopes it would fix it.  It did not.  I was reading through your list does my car have a speed sensor?  Where is it located?  And, how can I test to see if it is good. 

Answer: Your problem sounds like the speedometer cable should be replaced.

Question: 1997 E 300 D Mercedes mileage: 120,000.  Bob, Ken, speedometer just stopped working, both the odometer part and the mileage registration.  What should I look for as a laymen; some easy checks for me to do.  I’m not afraid to check things on my own.  Waiting for next move?

Answer: Check the signal generator in the transmission, replace as needed to repair the problem.

MORE: Speedometer questions

Repair Topics / Speedometer-1 / Speedometer-2