06-08 Sonata Automatic Question

Hey guys, I'm trying to figure out what Sonata V6 5-speed auto
tranny's are doing. Quite a few people (on another forum) notice that
the tranny feels like it's dragging, almost like it drops into gear
when you coast. Mind you, it's subtle, not a harsh deceleration like
an aggressive downshift.

On my car, with A/C on (dunno about off!) when I coast down from
~60mph, at first I feel no deceleration. Then, when the car finally
coasts down to ~40mph, I start feeling deceleration like the torque
converter has locked. The car then slows pretty quickly from ~40-0.

Does anyone have knowledge of how the tranny is programmed WRT the
lockup torque converter? At what speeds and gears is it supposed to
lock and unlock?

Also, the Sonata has a tricky A/C compressor that is supposed to
disengage under certain conditions. Could that be causing the slow
down?

Here's my reasoning for that question:

*When the A/C compressor is engaged, the engine idles higher.

*When you are driving and release the accelerator, at some point the
A/C compressor may be kicking off, in turn causing the engine idle to
reduce by 100-200 RPM. That would feel like a "drag", that could be
misinterpreted to be the tranny dragging. Make any sense?

Any knowledge as to whether the draggy feeling is normal or abnormal,
and the cause?

Many thanks,,,

-

Bob

 

Bob, watch your tach, or slip the shifter to the right(semi-manual mode) and
look at the gear indicated on the dash display.......

 

*When the A/C compressor is engaged, the engine idles higher.That used to be the case, but on my 07 Sonata GLS I-4 I have noticed that
the tach stays the same place with or w/o the A/C on(at idle). I'm sure
that's the ECU doing that.

Also My car coasts just great, maybe its only a V-6 problem.

 

I've noticed some engine braking, but wasn't paying enough attention to
know the exact circumstances to know when it was occurring. It didn't
seem unreasonable, so I pretty much assumed it was normal. Like one of
the other posters suggests, watch your tach and blip the gearshift over
and back to see what's occurring.

 

Agreed, it's subtle. It's not annoying at all.

It's just that we wonder why we are getting engine braking at an
unusual time. If torque converter lockup is programmed in at lower
speeds, it would be interesting to know why.
-

Bob

 

It's coincidental that you guys are talking about this now. For the last
several weeks I have noticed the engine braking on my '06 Sonata GLS V6 AT
being more pronounced than it was before. Maybe this is a function of the
life of the fluid or something similar? Not surprisingly, my mileage has
also dropped a bit, but tying that directly to the engine braking is not
possible statistically right now.

The weirdest thing is that I believe I have the same exact transmission in
my '07 Entourage. It has absolutley NO engine braking effect that I can
feel. It really is night and day compared to the Sonata.

Eric

 

I'm not even certain it's engine braking that is caused by the tranny.

It could be that the A/C compressor is kicking off at ~40mph, causing
a drop in engine idle RPM. That could possibly make it feel like it
was getting extra engine braking.
-

Bob

 

True. I could be either or a combination of both.

I don't think this is the case for me as it happens with the A/C off as
well and DOESN'T happen on the Entourage even with both compressors
running.

Eric

 

I think its downshifting. Mine seems to do it at 40 from 5 to 4, and 30 from
4 to 3......what does the tach and gear shift indicator(shifter in semi auto
and gear shown on dash panel) tell you?

 

One of the purported features of the TCM's fuzzy logic in newer vehicles is
that it'll monitor whether you apply the brakes when going downhill (no
word on what specific data it observes). If so, it'll downshift when
you're coasting downhill. If not, it won't. I wonder if clearing the
adaptive values (requires Hyundai scan tool) will change this.

 

Is the Hyundai Scan Tool available to the unwashed masses, or only to
service folks?

 

It's available to the masses for a small fee:

The price of Hi scan pro full kit for Hyundai is US$4,130 including
reprogram kit.
If you want only standard kit excluding reprogram kit, the price is
US$2,600.

Thank you.

Austin CHAE

www.nex-tek.com