This is going to be lengthy but it shows all my troubleshooting. We live in San Diego, CA. My wife’s car, a 2004 Hyundai Accent with 177,000 miles, has developed a transmission issue. Temperatures at night are in the 40s, day temps are 70s to 80s.

A couple weeks ago she had some problems, engine revving but transmission not kicking into gear immediately even though in DRIVE. I guessed and our mechanic Jeff confirmed it was a transmission problem. The transmission fluid had never been changed to my knowledge (we bought it used) so Jeff changed the fluid.

When he dropped the pan we found shredded metal, several about ½ in. long kind of like ribbon. There were also several chunks of metal about 1/8 in. dia.

He went ahead and changed the filter and cleaned out all of the metal in the pan. He put it back together and filled it with fluid. I drove off and the transmission performed great, just as it should.

The next morning around 5:30 I took it for a test drive. I noticed it would shift up normally ending up in 3rd gear. Going 50 mph it wouldn’t shift into Overdrive. I slowed down but it wouldn’t downshift but stayed in 3rd. I took it back home.

About 8:30 that same morning I took the car into town. The transmission worked beautifully, shifting as normal even into OD. It worked great the rest of the day. No noise, no smell.

The next morning about 8:00 I took it out again. The same thing happened, it shifted into 3rd gear and stayed. After about 6 or 7 miles I pulled over and put the car into P and shut the engine off for about 10 sec., restarted and took off and the transmission worked great. I drove at speeds up to 70 mph (legally), it shifted like it should, downshifting up hills and going into OD.

I stopped and talked with Jeff (our mechanic) telling him what I found. He was baffled. He thought that maybe the gears heated up enough to compensate for the missing chunks, just a speculation.

So the next day I started out with the same problem, staying in 3rd gear. I went about a ½ mile, pulled over and leaving the engine running I moved the shifter to P, then to L, then to 2nd, then to P, then to D and started driving again. The car stayed in 3rd gear. I went about another ¼ to ½ mile, stopped, put the car into P and shut it off for about 10 sec. Started up and took off and the transmission worked GREAT!!!

I took it back to Jeff and he ran diagnostics on it with no error code showing up for anything. I asked him if it could be in the computer since when I shut the car off it reset something so the car runs fine. He said he didn’t think so since there were no error codes on diagnostics.

The next day I started out with the same problem, stuck in 3rd gear. I only went ¼ mile or so stopped put it into P, shut it off for about 5 sec. Started back up and drove off with everything running GREAT.

A few days later I went out in the morning and started the car, I didn’t shift the transmission at all. I forgot something in the house so I shut the engine off, ran in the house, taking only 2 minutes or so, started the car and drove off. The transmission worked great!

So now we start it up, let it run for a minute or so, turn off for about 30 sec., start back up and go and the transmission works great.

My question is: Could it be a computer/sensor problem that is not registering because something resets after I shut the engine off without shifting the transmission?

 

your mechanic is right. That transmission is toast. Ive worked on imports for awhile and done my share of transmission work and from my experience if there's even so much as metal dust like shinys in the transmission fluid or stick to the pan magnet so much that you cant see the magnet it's over especially a hyundai accent or elantra. My 04 has bookoos of auto tranny recalls on it that's y i drive 5-speed ive seen trans at 100k that never got changed get fried. And flushing it is a 1-way ticket to turning that trans into scrap metal. Changing the fluid in a tranny that hasnt had regular maint (30 or 60k) can cause more harm than good. All the clutch material and pieces in the pan are no longer there hence the clutches cant grab. Besides, you found those pieces in the pan who knows what of those could be in the tiny tiny valves and pistons in the valve body that could be seizing or sticking. Bottom line if your tranny hasnt been serviced by 100k and there's no metal pieces you need to drain / fill it not flush - that'll kill it but drain it and change it every 30k. if you miss that or go past 125-150k it's a time bomb and you may as well drive it til it quits because servicing the trans after that point always causes problems

 

other forum --> http://www.hyundai-forums.com/t58282...r-please33.htm

 

Exact same issue here. Really hoping it doesnt need a whole new transmission. This link mentions similar issues being caused by pulse generators, temp sensor, or corroded wiring harness on earlier models:

2000-2005 Hyundai Accent: Full Review - Consumer Guide Automotive

But the two trans shops I brought it to so far immediately ignore that and just jump to the conclusion that its a $2k job....

 

Can anyone tell me where the Transmission fluid temperature sensor is located on a 2004 Hyundai Accent, Auto matic trans. Getting code p0713- transmission temperature sensor. Thanks in advance.

 

Does this require pulling the transmission or can it be done without?

 

There is no pigtail available for the wiring harness to plug into the transmission fluid temp sensor for my customers 2002 accent. Holy cow dealer says "new harness" for $1300.00 bucks! where can i find the connector to splice into this $2500.00 car??!!

 

Here are my Hyundai Accent A/T problems…
2002 Accent, 3rd owner, SoCal, 125K:
June 2013: CEL A/T codes detected: P0707 (Range sensor circuit low input); P0722 (Output speed sensor circuit no/low signal); and, P0734 (4th gear ratio problem).
Tranny would not go into O/D or 4th gear, only revved up rpms. Tranny went into safe mode and stayed in 3rd gear only. Hwy driving impossible.
July 2013: Professional A/T repairs done ($850):
1. New range sensor (P0707)
2. New output speed sensor (P0722)
3. New O/D bearing, race, filter, and added new A/T as needed.
Tranny shifted into all ranges, all gears. Hwy driving possible, but local driving only recommended.
August 2013: CEL A/T codes detected: P0707 and P0734 again, and P0740 (Torque converter clutch fault).
A/T fluid is full and red. Tranny is working as designed. But, due to codes, professionals recommended custom rebuilt tranny ($2,400.00). <Bought the car for $1,200.00 / Can’t afford any more expensive repairs>
Today – January 2014: No new work done since July 2013. The CEL is still on – assuming same A/T codes as in August. Tranny shifts into all gears and runs okay. 95% local driving, 40-45 mph. 5% hwy driving, 65-70 mph, only as needed.
I would like to feel confident driving on the hwy, but am afraid on any trip the tranny will revert back to June status – no 4th gear, only 3rd gear.
Can anyone help me with inexpensive DIY repair ideas? Any experience, advice, or suggestions to share? Thank you.

 

Who repaired the trans? Are they a qualified shop that knows Hyundai transmissions? Did they use the correct SP-III trans fluid? All other fluid will damage the transmission. Has the trans every been servised prior to the problems?

My guess is the work done was not done properly. I'd suggest finding another trans shop. No need for a "custom rebuilt tranny".

 

my 2003 Hyundai accent gl automatic trans went out at 140000 thousand miles. had it flushed and refill with Hyundai fluid every 60000 miles at Hyundai dealer. I bought car new from them in 2003.