Hi, A little about myself - I am a professional master autobodyman/painter with 36 years full time experience. At this point I'm semi-retired but still active in the autobody/paint field. I am also a decent mid level general mechanic.

I recently picked up a 2000 Hundai Elantra sedan with 109,000 miles for $500 with the agreement that the automatic transmission needed to be replaced. It won't shift past second gear. The previous owner ran a code scan and it came back as " 4th gear shaft doesn't match the rpm of the crankshaft" (not exact readout but close to that). I picked up an Actron sc9145 OBDII scanner which retails for close to $300 and it came back for me with no error codes. Its very possible the battery was disconnected by the previous owner then no driven out of first gear (driveway movement only, same since in my posession).

The previous owner automatically assumed the 4 gear clutches were shot and it would need a new transmission. I'm trying to eliminate any simpler fixes before I replace the trans. Any an all help will be very much appreciated. I will be happy to help anyone with autobody or autopaint related questions. thanks, Phil

Dear Phil,

You are absolutely right to try all of the cheap and simple fixes before advancing to transmission rebuild or replacement.

I always advise to do a fresh transmission flush just because it is cheap and simple. A power flush will clear most of the debris in your transmission hydraulic system, and just may fix your problem.

do go to hmaservice.com and register. Gives you access to the Elantra shop manual, OBD codes, and troubleshooting charts for FREE>

If you want to pay a dealer, the Hyundai dealership can connect to your car and run a complete diagnostic on your transmission with their SCAN Tool. It will map your shift points, show your transmission pressures, even diagnose wear. Just costs money for the diagnosis...something like $238.

Due to the 109,000 miles on the Elantra, this diagnostic will likely reveal some wear. You may want to just check the auto recyclers in your area to see if they have a low mileage Elantra or Tiburon 2.0 automatice transmission. You could elect to save the money from the diagnostic fee above and put it directly toward a replacement transmission from an auto recycler.

Byron

This post has been edited by byronguidry3732: Dec 26 2007, 05:29 PM

Hope its not too late, just joined the forum today myself.

I had this problem, its a faulty "speed sensor cable". Hyunai makes crappy quality parts, it's about a $100 part but because its considerered an electronic it may be non returnable.

You don't want to know the PITA that this problem caused me. Actually, don't get me started - I've had nothing but problem after problem with my 2000 Elantra wagon.

Thanks for the replies. Not long after my first post here I took the car for a ride around the neighborhood. No error codes(no check engine light). It seemed to shift fine but I didn't have enough room here in the neighborhood to get it up to speed in over drive so it shifted only 1 - 2 - 3. A couple days later I talked my adult son to follow me so I could take it out on a regular road to where I could get it up to road speed. I didn't even get out of the neighborhood and the trans was acting up bad. Seemed to start out in second gear and serious slippage between 2nd and 3rd gear. Check engine light came on so I pulled it back in my garage and put my actron scanner on it. Error code stated "4th gear rpm does not match engine rpm". I then cleared the error codes and checked the transmission main electrical plug. The retaining clip was broken off previously but the pins in the plug looked good and clean. I applied a dialectric grease liberally and plugged the tranny wire plug back in. Took it for another ride and this time it shifted fine 1st, 2nd and 3rd gear but slipped between 3rd and over drive (4th gear) Could not get it to go into 4th gear. Any ideas ??? Where is the tranny speed sensor located on the tranny ?

the vss is on the back of the dash hope this helps