2001 Elantra GLS - P1529 & P0455

Hello,

I know that P0455 is a vapor leak, most commonly caused by a loose gas
cap. This usually causes the light to come on and if you tighten the cap
or replace it with the dealer model, you can usually get it to turn off on
your own within 60 ignition cycles (correct me if I'm wrong, PLEASE!).

However, according to P1529 explinations found in these forums, that's
simply a code explaining that one system on the car asked another system
on the car to turn on the light - but no reason as to why (usually
accompanies other codes, would be my guess).

Well, I replaced the gas cap weeks ago and the constant light for that
problem turned off shortly thereafter. The problem I'm experiencing now is
this:

I start the car from either a cold or warm state (I've noticed it happens
more often if the car is warm). The light is NOT on when started. I drive
down the road at speeds under 60 mph (usually) and the car suddenly jerks
like it was pulled out of gear during movement (not very severe at low
speeds). The light comes on and it acts like it's in a high gear (lots of
rev, high RPMs (over 1000 more than normal), slow to accelerate but
otherwise operates fine.

Now here's the tricky part - if I cycle the car at, say, a stop light, the
light turns off and about 75% of the time I can complete my journey without
any reoccurances. In either case (even if it does reoccure in the same
trip), if I turn the car off and back on again the light clears - only to
return once the whole gear jerk sensation / gear shift thing happens
again. This happens about once a day on average.

It's only done this once while on the freeway and I was going about 65 at
the time - BIG jerk that time. I'm very concerned it's going to damage my
car badly at this point. The dealer said that so long as it's not doing it
constantly, I can get away with driving it until I have the money to fix
the problem. To even have them run diags on the car it's 90 bux so I had
Autozone pull the codes for free.

Can someone explain a) why the car is doing this? b) what damage might be
happening because of it? c) why it is intermittent (why does it do it
sporatically and not every trip)?

The dealer rep, without knowing the codes and only the symptoms believes
it's the overdrive sensor failing, causing the car to not shift into
overdrive.. he thinks "something" (I can't remember what he said right now
but can find out) is dirty and that nine times out of ten simply cleaning
it can take care of the problem (I think it was a sensor device of some
kind).

Anyway, any insight you can provide would be wonderful. I'm trying to
avoid 300 bux in labor if I can at all avoid it.

Thanks,
Bob

 

If the dealer rep you talked to actually used the term "overdrive sensor,"
then he doesn't have very much knowledge about your car, as it doesn't have
one.

The P1529, jerking, and driveability issues are because you have a
transmission issue. P1529 means the trans computer requested a check
engine lamp. The jerking happens when the condition actually occurs. The
being in high gear occurs because the transmission computer is putting the
transmission in failsafe (3rd gear only). Cycling the key will take it
out of failsafe. If you continue driving like this, you could damage the
transmission. There will be dtc's stored in the transmission computer
which will help identify the problem. My guess would be an input speed
sensor, but there are many other possibilities.

 

Lovely. I'm trying to recall if he used that term or if he said "The car is
not shifting into overdrive the way it should be" "It might be because of a
sensor problem" (or something to that effect).

Anyway, I recently had a goodyear shop replace my transmission fluid. Do
you think they might be responsible for this behavior, since it didn't
happen before they worked on it?

 

I'll let hyundaitech be the judge, but I can almost guarantee you that the
Goodyear place put the wrong transmission fluid in the car----Hyundai
transmissions use a special transmission fluid that is rarely, if ever,
available at those shops----

 

The wrong fluid is unlikely to cause a problem like this right away.
Problems from using the wrong fluid tend to manifest themselves over time.
There's a possibility they did not properly fill the transmission. I'd be
real interested to find out exactly which fluid they installed, however.
Anything other than SPIII is incorrect.

Our shop, for example, buys some ridiculously expensive junk bulk fluid
whose specs supposedly meet the requirements of about a bazillion
different vehicles and manufacturers. I figure this is impossible given
the differing friction requirements of these fluids. Needless to say,
this fluid doesn't touch a Hyundai.

 

Very interesting... I found some financial help and took it into the
dealership to get the official "this is what's wrong with it" story.

I did ask them if Hyundai's use a special transmission fluid or not and he
hesitated, looking for the right phrase to use. In the end he said,
"Basically, ATF is ATF. The wrong fluid could cause problems, like usually
you'd see irratic shift patterns over time, and things like that." He never
mentioned anything about SPIII, or anything to do with a shop needing to be
very particular about what fluid to put in the car.

Anyway, they're running the diags now and will let me know the story
soon.. at which time I'll post the results so you can keep up with
everything.

Thanks for your continued feedback here, it's really helped me to keep
everything straight.

 

By the way, for the hell of it, I decided to call the poor unsuspecting
sales rep over at the goodyear shop I took the car to a few weeks ago, and
asked him for the specific brand of ATF they used in my car. He said
"Valvoline Maxlife ATF" - a description of which can be found here:
http://www.valvoline.com/pages/products/product_detail.asp?product=6

Thoughts?

 

Alright, the dealer came back with their findings but they didn't speak to
me directly (I was working at the time). They said that there are three
sensor failures, one of which can wait until later (evac or evap sensor -
I'm unclear on that). The other two are (I think) a "drive sensor" and a
"speed sensor". When the work completes tomorrow and I have the paperwork,
I'll update this with the official names of everything - but there was no
mention of the fluid or any problems with it. Thoughts?

 

So far sounds consistent. The evap problem is your P0455. I'd need more
complete names on the others to understand exactly what's going on.

If the info you posted is correct that Maxlife is DexronIII/Mercon, I
think I'd call Goodyear back and demand that they either reservice the
transmission with the correct fluid or demand that they reimburse you for
the expense you incur for having the fluid changed again at the dealer.

And no, ATF isn't ATF. Most new cars now use what are called proprietary
fluids which are expensive and designed to meet your car's specific needs.
The incorrect transmission fluid can cause shift quality issues, and over
time, it can cause unnecessary wear. It's important to use the proper
fluid at all times.

 

I have no problem demanding this, but I'm gonna need some sort of
documentation on the ATF requirements for the Elantra, or I'm gonna get
refused. Can you provide a link to something?

 

The requirements for fluids should be stated in your owners manual.

 

The owners manual states the kind of fluid used, but doesn't say anything
about it being required. Without something concrete from Hyundai or the
dealer stating that this type of ATF is the ONLY thing that should be used
in their tranmissions, I'm afraid I won't have much luck convincing a major
corporation to pay $100+ to do another fluid change.

 

Also, the paperwork states they replaced the Cam sensor and the Speed
sensor. Does this make sense? Since the repair the driving problems have
ceased but I am noticing a slightly odd shifting pattern, so perhaps the
fluid is causing that?