I posted a transmission problem back on the 21rst of December. Thank
you much Hyundaitech for your advise, yet I have to implement the
solution. In short I ended up having more important issues to deal
with. Rough running, very sluggish, and odd engine revving. I've
replaced plugs, wires, air filter, fuel filter, and fuel injector
wiring harness that I busted when doing the plugs and wires. That has
taken care of the rough idling and driving. I still have another
problem, along with the ongoing transmission problem (which I will re
quote at the end of this entry) after driving 50 some odd miles to or
from work on occasion the engine upon slowing down will start racing
and slowing down. In neutral it will rev up to 3500 and back down to
1500 only to rev back up to 3500. I have to apply the brakes to stay
within the suburban speed limits. This behavior goes on and on until
another re-start. I'm hoping this is related to the transmission
trouble so I can concentrate on replacing the two speed sensors. I
drive this car 108 miles a day to and from work, and since we paid it
off two years ago I want to keep riding out the equity with as little
money input as possible. It is still running very well all considering
it has 124K on it and when running well I do put her through her paces.
Thank you to those who tell me to take it to a competent garage, but I
prefer to work and learn. When I get over my head and know it, I push
the ol' girl down the street to a garage I trust.(i.e. when I don't
have the tools or time)
>>>>>>>>>>>>>>
I've been having this trouble for some time now. I could be driving at
any speed when the transmission will drop down a gear and stay there.
If I restart the engine the tranny will shift properly until this
problem reoccurs. I have codes too. P1529, I have no idea what that one
is, I was told it is a manufacturer specific code. P0720 "The PCM has
determined that a malfunction exists in the electrical circuit for the
output speed sensor" . P0715 "The PCM has determined that a malfunction
exists in the input circuit for the turbine speed sensor." Please help
this is driving me insane.

 

No issue with the transmission can make the engine run abnormally fast when
you're idling.

Check your throttle cable to be sure it is properly attached and nowhere
coming out if its crimps. Be sure you have slack so that the throttle
plate isn't held open.

Also check the wiring to the throttle position sensor and the sensor
itself if you can. Rereading the trouble codes would be a good idea just
to see if anything new has appeared.

Check your PCV hose to be sure it isn't developing a hole.

 

hyundaitech wrote:
> No issue with the transmission can make the engine run abnormally fast when
> you're idling.
>
> Check your throttle cable to be sure it is properly attached and nowhere
> coming out if its crimps. Be sure you have slack so that the throttle
> plate isn't held open.
>
> Also check the wiring to the throttle position sensor and the sensor
> itself if you can. Rereading the trouble codes would be a good idea just
> to see if anything new has appeared.
>
> Check your PCV hose to be sure it isn't developing a hole.

I stopped by autozone this afternoon to get the codes. Here is what I
have P0765: The PCM has detected a malfunction in shift solenoid "D"
P0760: The PCM has detected a malfunction in shift solenoid "C" . The
rest of the codes are re-occurrences. P0720: The PCM has determined
that a malfunction exists in the electrical circuit for the output
speed sensor P1529: Scair solenoid cicuit malfunction and the last
P0118 The PCM has determined that the input from the engine coolant
temperature sensor is higher than expected for the current engine
operating conditions (I bought a new coolant temp sensor today and will
be installing it this week)
So, I can assume with the work I've done has probably messed with my
throttle cable.
BTW, the Hyundai web site used to have a parts breakdown/ diagram. I
can't find it on the hmaservice site. What am I missing?
Hyundaitech, you freakin rock my socks off! Thank you for all your help!

 

If you're looking for pictures of the individual items, you can find the
links in the ETM section. At the bottom of the schematic, there's a link
for component locations. After clicking, select the component you wish to
see.

P0760 and P0765 cause me some concern. You'll want to check the TSBs at
www.hmaservice.com for detailed information on how to approach these.
Unfortunately, you'll need to remove your radiator to get the transmission
pan off.