2001 Hyundai Elantra Code P0720

2001 HYUNDAI ELANTRA
97,000 MILES • 4 CYL • 2WD • AUTOMATIC
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ALLENK
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Replaced vehicle speed sensor ( SU 6201 Autozone #) located on tranny. Code is still comng on the next day. So I took off the right front wheel ,to look at the sensor, behind and to the rear of the brake disc splash cover. Took it out and clean it. Looks OK ??? ( I think its called the speed out put sensor) Anyway do I need to reset computor??? And please tell me how to anyway, because I can,t find a clear answer about it anywhere !!!! Right now the car sits ( with the negative battery cable disconnected and the key in the run possition ) It,s probably been a couple of hours since I took the batt. cable off.
Mar 16, 2009 at 5:37 PM
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BMRFIXIT
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Check the connection and wiring


https://www.2carpros.com/forum/automotive_pictures/99387_Graphic2_122.jpg


https://www.2carpros.com/forum/automotive_pictures/99387_Graphic3_59.jpg

Mar 16, 2009 at 5:58 PM
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ALLENK
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Thanks but I can bearley see it !!!
Mar 16, 2009 at 6:13 PM
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BMRFIXIT
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would you like them emailed ?
Mar 16, 2009 at 8:28 PM
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ALLENK
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Yes, I was also hoping you answer the ? of how to reset the codes. ( If you need to at all) This subject ( of P0720) is on varrious websites. But I can't find any that repair it themselves & used laymens terms>
Mar 16, 2009 at 8:38 PM
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BMRFIXIT
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Use a scan tool or disconnecting the battery would be the same no special procedure to resetting the codes
on this or any other car
if light return than the repair was not done correctly and the problem still the same
need to check the wiring harness if changing the sensor did not work for you
Mar 17, 2009 at 5:52 AM
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ALLENK
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Thank you I will return with the results!!! (So that everybody can learn from this)
Mar 17, 2009 at 10:41 AM
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ALLENK
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https://www.2carpros.com/forum/automotive_pictures/332474_20070622102731_1.jpg

Today, I will take it to the dealership. I have done everything mentioned. I think this car has been parked long enough. Since last post it has been driven only about 50 miles.
Oct 3, 2009 at 11:41 AM
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BMRFIXIT
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Woo still not driving it
!!!
let us know what was the end result
when done
Oct 3, 2009 at 7:13 PM
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ALLENK
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Well it helps to have two other vehicles to drive. But the Elantra is my (work) economy car.
Oct 4, 2009 at 9:49 PM
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ALLENK
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Just heard back from the dealership !!!! They said the transmission has internal problems. I wonder if it might be a bad TCM. I mean it ran 8 miles just fine on the way to the dealer, then ca-chunk and the engine light is on agian, 1 mile from the dealer. I could see maybe if it was sliping all the time or something. I saw a used TCM for $ 50. I thought I might give that a shot before I replace the whole transmission. Otherwise the Elantra will be sitting for a while again. I guess this is a good way to keep the miles down. I sure hope this will help someone else in the future. " I"LL BE BACK"
Oct 5, 2009 at 4:13 PM
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BMRFIXIT
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Poor Elantra !!


for $50 take a shot at it
let me if it worked
Oct 5, 2009 at 4:57 PM
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ALLENK
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Well, I thought I replaced all the sensors , but I was wrong. After going to HMASERVICE.COM I found that the input sensor is by the air filter box. Not by the front right wheel .I have overlooked this (input) sensor. So I went to the wreck yard to see if I could find another, just to see if it would make a difference. I found most of the cars already missing this sensor. Finally I found one. The car was totaled from a head on crash, so I assumed it was running when it got hit. I went home and put the new sensor in, still got an engine light. I drove to Auto zone (3 miles), with no problem. I was going to have them do a code scan. I thought maybe that would clear the codes. When I got there I shut off the engine. Then I decided to to see if the code was still there, by starting it back up. The engine light didn't come back on. I decided I needed to put more miles on it to see if this was really the correct fix. So far 75 miles and no symptoms.

I have tried to do this in simple terms, so that it could usefull to everyone.
Oct 17, 2009 at 2:20 PM
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BMRFIXIT
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Thanks for the update that s a great news
happy driving
Oct 17, 2009 at 2:28 PM