1999 Hyundai Sonata Shifting problems

Tiny
BRAD&AUDREY
  • MEMBER
  • 1999 HYUNDAI SONATA
Transmission problem
1999 Hyundai Sonata 6 cyl Automatic 167000 miles

My daughters Sonata has a strange problem. If when she tries to start it, it doesn't start the first time then when it does start it doesn't like to shift gears and when you stop it locks up just before you stop (I believe it's the transmission downshifting into first)
Tonight at a light it just died. She started it up again and it happened all over again.

Normally to get it to 'reset' you turn it off for a minute or so and everything is fine.
Tonight the Check Engine light came on and she doesn't remember that happening before.

Sorry I don't know if it's a front or read or all wheel drive. I can find out.
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Saturday, June 14th, 2008 AT 12:38 AM

11 Replies

Tiny
KHLOW2008
  • EXPERT
Hi Brad&Audrey,

Get a scan done to find out what the code is and let us know.

What do you mean by locks up? Even in 1st gear, the car would still move forward.
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Saturday, June 14th, 2008 AT 1:37 PM
Tiny
BRAD&AUDREY
  • MEMBER
My son in law, trying to fix the problem unhooked the battery clearing the code. He will get the code next time it happens.

Coming to a stop, pressing on the breaks, the combination of what feels like a downshift (per the son-in-law) and the breaks being pressed the car just stops. More like the breaks grabbing but s-i-l thinks its both.

Thanks
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Saturday, June 14th, 2008 AT 2:54 PM
Tiny
KHLOW2008
  • EXPERT
Hi Brad&Audrey,

Looks more like harsh downshift which is mostly caused by the valve body solenoids.
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Saturday, June 14th, 2008 AT 3:10 PM
Tiny
BRAD&AUDREY
  • MEMBER
Sorry if this shows twice, somehow I lost the first reply.

It happened to me. Was at a stop light and when taking off it acted like it didn't want to accelerate or shift. By not giving it too much gas could get up to about 50 mph (didn't feel like it would shift into top gear).

Error code is P0335 Crankshaft Position Sensor. Does this make sense based on the problems we are having? Hopefully, this is the part but where is it and can I change it?

Thanks,

Brad
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Saturday, June 14th, 2008 AT 6:23 PM
Tiny
KHLOW2008
  • EXPERT
Hi Brad&Audrey,

Yes, the crank shaft sensor would cause difficult and at times impossible to start. It would also be related to improper ignition timing.

I am not sure of the engine that you have but for most Hyundai the CKP sensor should be located behind the crankshaft pulley next to the timing belt. You need to remove the timing belt cover to get access to it.
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Sunday, June 15th, 2008 AT 6:39 AM
Tiny
BRAD&AUDREY
  • MEMBER
Thank you very much for the advice. I'll get the part ordered and start looking for where it goes. Do you know of someplace I could get a picture of where it is?

1999 Sonata V6 - I've seen it called the Sonata (EF).

Thanks again,

Brad
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Sunday, June 15th, 2008 AT 1:29 PM
Tiny
KHLOW2008
  • EXPERT
Hi Brad&Audrey,

Sorry I can't assist you on the picture or diagrams as I am not very familiar with this engine. But if it is similar to the Mitsubishi V6, then it would not be easy to replace.

You need to remove the crankshaft pulley and timing belt covers.
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Monday, June 16th, 2008 AT 6:59 AM
Tiny
BRAD&AUDREY
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Thanks KHLow2008,

I called the dealer service center and they told me where it was. It sits just above the starter, pull the starter and you have clear access to it. Problem is we couldn't get the starter off so with some persistance and effort we were able to replace the sensor. The old one had some exposed wires which were probably driving everything nuts.

Now we have a new problem showing, the car still shifts rough, worse than before and we are getting a different error code P0720 - Output Shaft Speed Sensor. Anyone know anything about that? Checker doesn't show them available so it's probably a dealer thing.

Anyone know where it is and can I change it? Also, does anyone know why Chilton and Haynes (I think those are the names) don't make manuals for this car? 1999 Hyundai Sonata V6?

Thanks again,

Brad
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Monday, June 16th, 2008 AT 10:16 PM
Tiny
KHLOW2008
  • EXPERT
Hi Brad&Audrey,

During replacement of crank sensor, you might have dislodged or broken some wires.

The output shaft sensor is mounted on the trans. Check around the starter area. Should look quite like the crank sensor from outside.
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Tuesday, June 17th, 2008 AT 8:17 AM
Tiny
BRAD&AUDREY
  • MEMBER
Thanks, that was my first thought - located teh speed sensor and it's about 2 feet away on top of the transmission. I traced the wires back and they look OK.

I did find a Technical Service Bulleton on this part on the Hyundai web site (for my model and year) would that mean that they would fix/replace it for free?

Thanks,

Brad
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Tuesday, June 17th, 2008 AT 9:57 PM
Tiny
KHLOW2008
  • EXPERT
Hi Brad,

Check with the dealership to see if they would do it for you and ask why if they refuse.
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Wednesday, June 18th, 2008 AT 6:47 AM

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