6th May 2010, 11:04

I own a 2001 Hyundai Elantra. The check engine light came on and the code indicated an input speed sensor problem. When the input speed sensor in not working properly, the car will kick into 3rd gear. When this happens, just pull over, stop the car and restart. Your check engine light may stay on, but your car will run OK without damage. Sometimes the check engine light would stay off and remain off for several days, but the event would happen again. I had the sensor replaced. Cost about $180.

About 6 months after replacing, the problem has returned. From other Internet site postings, I am learning that this is a common problem, perhaps a fault in the sensors themselves. The problem can occur with a fault in either the input or output sensor. The important issue here is to stop the car ASAP and restart before continuing your journey. I don't think any damage is done to the transmission if you drive with the check engine light on, as long as you can tell the car is shifting gears appropriately.

29th May 2010, 21:18

2006 Elantra headlights keep blowing...

At first I thought it was the Sylvania bright bulb's fault; 1 blew and not other...

Then I tried pilot bright white blue. BOTH blew a few months later.

Then a pair of basic lamps... guess what happened - blew...

Paid service department to replace... 1 month blew... 1 of the 2 new they put in...

Went back, and this time they replaced that 1... its been 6 months since this started, and they just replaced both again...

THEY NEED to FIX these lamps because something is wrong...

I have a electrical engineering background, and I know it's probably a voltage regulation issue... funny, because 2 months prior there was a guy going irate about his lamps when I took it for an oil change at the dealership...

These last few times, figured if I take it to the dealership, then its documented with them... before I request they look at the wiring...

14th Aug 2010, 14:09

I have a 2001 Sonata and a 2001 Elantra; both cars are A/T, and had the problem of suddenly dropping down into 3rd gear. This turned out to be the input and output speed sensors. You can buy both of these on an eBay store for 1/2 price of the dealer (about $83.00 and that includes shipping). It is easy to replace these, and it only takes about 20 minutes.

Remove the air breather and disconnect the battery. The sensors are on top of the transmission. Here is the link to parts: http://stores.ebay.com/FourGreenAuto

22nd Aug 2010, 21:47

I bought a 2001 Elantra 2 years ago, when it had 59k. It has 73k now and I have been pretty happy with it.

A few blown headlights, of course, including both at once while I was driving home at night through Pennsylvania… The dealer guarantees the bulbs for a year if they change them, but I opted to do it myself.

I had to change a speed input sensor, the radiator (small leak), power steering fluid hose, and the check engine light is on every time I do not tighten the fuel tank cap 6 times. I have it on again and an auto parts store read my code: they say it is sparkplug no. 2. I have just replaced the sparkplugs, although they were still good, with 4 identical new ones, so I doubt there can be a problem already.

28th Aug 2010, 16:06

I bought my wife a 01 Elantra new in March of 01. All I can say it has been one of the best cars I have ever owned.

It has just hit 80,000, and has had some minor issues.

A coil went out and was covered by the dealer.

It eats low beam headlights (no big deal).

This year, 2010, it has had its first set of front brake pads, I replaced both front CV joints, and I just replaced the timing belt I know I waited too long. But it got done by me and cost less than $100.00 for the timing belt tensioner and three belts.

I have worked in automotive parts sales for the last 12 yrs. I don't see a lot of requests for Hyundai parts. Maybe it's because they're good cars or because of the good warranty. Besides regular maintenance items that most cars require, I just don't see many parts going out the door for any Hyundai.

So to all of you naysayers, I believe you're either being taken by your mechanics, or you're beating your car like a rented mule. I will buy another one if I ever wear this one out, which doesn't look like that will be anytime soon!

28th Sep 2010, 15:58

I have a 2001 Elantra, and it only has about 63,000 miles. This weekend it started the gear thing where it shifts really hard and the engine light comes on. We took it to the place where we get the oil changed, and they checked it, and it came up to show output speed sensor. I had to set up an appointment with the dealer for Monday for them to check to see what is causing it, but after reading all of the above comments, I am pretty sure I know what it is, but the dealer will not be replacing it. The people at the oil change place recommended a reputable mechanic that they refer to customers. I have never had any other problems with this car since I have had it, other than recalls. The only reason my next car won't be a Hyundai is because the man who greets you at the service counter is a total jerk, and very, very rude.

1st Oct 2010, 10:05

I own a 2001 Hyundai Elantra automatic, and I've been driving this car for 8 years, and I drive my car a lot. I live 20 miles from civilization, and the car has 160,000 miles on it.

For the most part, it has been a good car. It's seen me thru high school and college. But I have had so many problems... it will not pass inspection, and the problems just keep popping up.

My check engine light is on. At first it was the O2 sensor... fixed that. Then it was the speed sensor... fixed that. Now they are saying it is another speed sensor, either the input or output. On top of that, ever since I have owned the car... I have replaced the transmission (my fault), radiator, starter, seems like 1000 light bulbs since they blow all the time!

Also, like others have said, it is very difficult to see at night, even with the high beams on.

My check engine light is on, and I can't seem to get it to go off, and it is just sucking way too much money out of me...

Any suggestions on the input and output speed sensors? Please help...

21st Oct 2010, 14:55

My Hyundai Elantra 2001 has been having the start problem for about a month now, and right now it's not starting at all. I bought it used with 101k miles on it in May, and it's been running fine. All I had to replace were the minor things like brakes, headlights, and fluids.

Then one day I go to start my car, and the engine shut off after some weird shaking. I waited there for about 15 minutes, and tried it again, and it was fine. For a month, it's been doing the same thing. I had had some friends and a mechanic look at it, and they said there was no problem with the starter, battery, or fuel because it runs SOMETIMES until now.

It has started at all for the last 4 days, and I can't take it to the dealer because I can't get there. One of my friends is a mechanic, and he's looking into it now, and thinks it could be the fuel filter. Anyone know where it's located so he can check it? Also give me some ideas of what else to check, if you recently had this problem and got it fixed. This is so I can have him check it.