Hello every one.I have Hundyai XG2001 95000 miles. Last week my check engine light becomes on. When i checked the code it says P0720- O/p speed sensor. I checked with pepboys they says the out put speed sensor is fine,transmission fluidis balck so check with Amaco. i checked with them they says that O/p speed sensor is not able to reconize the speed becuase of some metal paricles in transmission and they have to rebuild my transmission, clean it & to check if any part of trasmission is damaged. It would cost me a lot. Can i do the transmission flush or Only changing the transmission fluid will reduce the problem? Is the transmission flush procedure will be safe for trany of my car.

This post has been edited by pravin.agarwal2: Jul 11 2008, 10:14 AM

Maybe,

Part of the problem might be your mileage. Many times I've seen where doing a flush with high miles and no prior maintenance causes more issues. I've done trany flushes and repairs for over 30 years and the story of low maintenance never ends. Tough call without being able to see it.

Your second question. " Is the transmission flush will be safe for tanny of my car."

Hard to say for sure what you're asking, your grammar is poor. I'll assume you're asking is a flush solution or a flush procedure safe. My response would be the same as above.

Amaco could be right. I've seen it many times.

You state, "fluidis balck so check with Amaco". Black fluid is a big no no. You do need to do something.

What might be the thing to try is just a drain and refill. See if any improvement is seen. If so maybe a flush without using a power flush could be in order. I cover this procedure on my yahoo blog.

Good luck

This post has been edited by cmhj2000: Jul 11 2008, 09:25 AM

l would agree with the above post, changing the fluid may not work but it's worth a try, make sure you use the hyundai SP111 fluid

Ya doing a tranny flush on a high-mileage tranny, unless you've been doing it all along, could grenade it. Seen it time and again. But as far as the fluid being BLACK.. that's certainly not good. Bad news man. I'd call multiple shops and see what they have to say, ya know? Thats why it's good to have hook ups?

The microscopical metal dust is normal on high milage on sensors, the mechanic can read the reading of both input and output sensors. So if there is a 0 for reading its a shitty sensor and worth changing ASAP, because if one or both sensors are 0 for more than 5 seconds the tranny locks up at 3rd gear.
If the tranny locks up at 2nd gear its oiltemp.sensor fault.

This post has been edited by Mihkel: Jul 11 2008, 04:12 PM

Car has automatic transmission and Check engine light goes off if i will not drive car more than 1 day.Again after 15-20 miles it comes up.I checked the O/p speed sensor with pepboys they says there is no problem in sensor.