Hello, I have a 2002 Hyundai Sonata v6 automatic transmission. The car has about 75k miles on it and I've owned now for over 4 years with no problems what so ever till the past few months. The other day I drove it up into the mountains for the day and back home (about a 200 mile trip one way). No problems on the way up, but on the way back home I felt a minor slip in the transmission after 3rd gear and the check engine light came on. I got worried now because I had an almost 3 hour trip back home. I got onto the freeway and was doing about 60 mph and noticed the car was reving rather high around 3500-4k rpm. Usually at 60-65mph its down near 2-2.5k rpms. I carefully pulled over to the side of the road went to a complete stop and tried again, I noticed it had a very slow pick up. I pulled over again and decided to manually shift with the shifttronic. At 0mph and idling around 800rpm I popped it over into shiftronic and it was displaying me in 3rd gear at 0mph. I tried to manually shift down to 1 and it wouldn't let me it would only go to 2nd. I took the next exit to find the nearest auto store. I got to the autopart store and the employee said all the tranny shops were closed for the day but he looked at my tranny fluid and said I was a quart low and he put some more in for me.

Now, really worried with a partially steep up hill drive home the auto guy told me I could make it just to drive real carefully and slow. So I did. But the weird part is after the car was off a few mins while at the autostore (check eng light still on) it was shifting from 1 on up fine. I made it home going about 60mph at 2krpm the whole way with almost no stops just to be safe.

I recently took the car out today (24hours later) to get it scanned for free at autozone. The check eng light is now off and these 2 codes turned up.
P1529 Manf. Control Veh.Spd. Idle Speed Control Auxiliary inputs.
P0715 Input/Turbine Speed Sensor A circuit Malfunction.

About two weeks or so ago the check eng light came on and it was the transmission speed sensor, which I got replaced. Could this have any effect on my current problems and can anyone please enlighten me to what all these codes mean and if they correlate to my above story?

I am realllly hoping I don’t have to drop a lot of money on a brand new tranny and its only something minor.

Thanks

 

Code 1529 is a general code which means you have a transmission error code. It means nothing by itself.

0715 is the speed sensor code, which you had replaced.

Sounds like your codes never got cleared after you replaced the speed sensor. Codes are stored in memory and don't erase themselves.

Did you ever change the transmission fluid.

You were A QUART low? That's pretty bad.

So it works ok now?

Here's what I would do:

Have the codes cleared. You can do this yourself by removing the negative battery cable off the battery for 15 minutes.

Take it to the Hyundai dealer and get the transmission flushed.

See if the problems happen again.

 

Hmmmm come to think about it, didn't even notice that these two codes were the same two that came up a few weeks ago. But I have been driving it now for 2 weeks after the fix and nothing with the gears being stuck ever came up why now? Was it the long drive? Could something be loose and causing it to malfunction? I will look into getting the transmission flushed (how much does this run on average?) Ill take it to AAMCO and see if they pull up a different code but i doubt it. Couldn't hurt to double check though.

One last thing, when I got the scan about 2 weeks ago done, the employee told me that P0715 said something about Transmission Speed Input Sensor, today it said P0715 Input/Turbine Speed Sensor A circuit malfunction. Nothing on the code said Transmission Speed today.. Dont know if that helps your assesment.

Thanks once again

 

Don't take it to Aamco, take it to the dealer because you must use the Hyundai spec fluid, not a universal fluid.

P0715- Transmission input speed sensor. It's all the same thing.

Just clear the code and see if it happens again first.

 

I bought an Elantra 2001 with 121,000 miles, 3 months back.

2 weeks back, while doing freeways the tranny jerks and goes to third gear.This was very rare. once i restart the engine, the check light goes off and the car is fine.

I got all the fluids refilled and found that tranny was short of 2 quarts. After refilling, after 1 week, the problem became more rampant on freeways, the check engine light used to stay on for 2-3 days.

I took it to the aamco, when the engine light is off, they gave me two codes
P0715
and
1529.

So, I bought the input speed sensor and got replaced at local garrage. They didn't reset the battery.

yesterday while doing freeway, the problem reappeared and I restarted the the engine, the check light is gone, the car was fine and i also did a 30 mile drive on freeway.

How important is it to reset the battery and for how long i need to disconnect the battery.
Considering the miles on tranny, can there be any hidden problems?

 

I had a 2000 Hyundai Sonata with the 2.5l V6 and 4 speed automatic. It did the same thing described above, stuck in 3rd gear, until you turn the motor off and start again. It turned out to be a couple of sensors. It turns out that when one goes the other blows out too. The car had close to 100k on it. All under warranty. The beauty of the 100k warranty. :-). So pleased witht he warranty I bought a 2006 Sonata.

 

Do you mean, the output sensor is also a probable culprit?

Next time, when the check engine light comes on i will take it for rescan.

 

Update: I had the transmission looked at. Turns out the sensors are working fine, but due to a warped drum, bad torque converter and burnt out sensors and solenoids. The signal was being messed up internally on the transmission. Had them fixed and now I have a power steering fluid leak which needs to be replaced. Yay more fun and money.

 

Sounds like you could have bought a whole extra car.

 

Just about especially with the price new cars have dropped . So my new problem is a power steering fluid leak where it goes to the rack. I had some dye put into the fluid and am going to drive it a bit, and use a blacklight to double check where the leak is coming from. From what I've read this is another common problem associated with Hyundai cars. Its not a serious leak its only a slow one.