[missourimule]

Today, I was driving my 2011 Forte 5 SX when it suddenly "clunked/boomed" at about 30 mph and I went on and I thought I had possibly run over something or hit a very big pothole. I turned around and double checked and that was not the case. Then I noticed that it didn't seem to shift properly. In fact, it wouldn't move out of fourth gear even though I moved the shift paddles. Drove it about one more mile and stopped in to do some business and when I drove away it stated in 4th gear. Drove it a little while longer and it seemed to "fix itself." However, 25 miles up the road the TPMS light came on. It was first a solid symbol. I pulled in to check the tires and they were fully inflated so I drove on (I was on the way to the dealer). Then it started blinking, again turning solid and then went out in about 45 seconds.

When I arrived at the dealership I told them what happened and they hooked it up to their diagnostic equipment and out came the following:

"P0748 Pressure Control Solenoid Value, C1312 Sensor 1 Radio frequency test drove found trans working, cleared codes, OK now."

This was a warranty matter as I only have 5,300 miles on the clock and I have never abused it. The transmission is the six speed automatic with 2.4 engine. It has always shifted perfectly previously and in fact is now again shifting perfectly.

I was told to bring it back if it repeated the problem. It didn't repeat any of the problems related after I left the dealership.

Q: What do these codes really mean and what on earth would cause the TPMS light to suddenly appear, start blinking, turn solid again and then go out on its own? There must be some kind of connection, I would think.

Who is the Kia tech/expert here who can shed some light on this weird problem.

These are the only problems I have experienced with the car that I purchased last November.

 

[arinesmith]

The pressure control (PC) solenoid valve is an electronic device that regulates transmission line pressure based on the current flow through its coil winding. If that had an issue, then you weren't getting good pressure in your transmission fluid and that sounds like it resulted in the clunk and 4th gear issue.

The second error code indicates an issue with the sensor transmitting its signal. As I understand it (and the error code makes sense) is that the sensor in the wheel uses a Radio Frequency (RF) to transmit to the TPMS. I get the TPMS error sometimes when I drive by a local airport.

Both happening at the same time could be coincidence or some electrical issue that provides power to both.

 

[noodile]

just so you know, TPMS lights means there's an error with the TPMS system, not a low tire pressure.

low tire pressure has a different symbol than the letters TPMS

 

[arinesmith]

just so you know, TPMS lights means there's an error with the TPMS system, not a low tire pressure.

low tire pressure has a different symbol than the letters TPMS

I actually learned that here on the forum. The low pressure looks like a ((!)) or so. TPMS is oddly enough "TPMS".

 

[Tebore]

Stories like this scare me. Electronics are awesome when they work but they are a bitch when they fail. They so cryptic in their failure and so misleading. For all you know it's a one time glitch caused by a solar flare or it's a partially defective ECU/TCM that has a bad solder joint and will never reappear until your 11th year of ownership. And electronics are usually contracted out to the lowest bidder.

 

[missourimule]

just so you know, TPMS lights means there's an error with the TPMS system, not a low tire pressure.

low tire pressure has a different symbol than the letters TPMS

It looked like the same symbol that I had when I did have low air pressure due to picking up a nail sometime back. When it was repaired and the air pressure was normal the symbol went away. Had the ! in the middle of a outline of a tire.

I should check the manual for the difference. It was just totally weird.

 

[missourimule]

The pressure control (PC) solenoid valve is an electronic device that regulates transmission line pressure based on the current flow through its coil winding. If that had an issue, then you weren't getting good pressure in your transmission fluid and that sounds like it resulted in the clunk and 4th gear issue.

The second error code indicates an issue with the sensor transmitting its signal. As I understand it (and the error code makes sense) is that the sensor in the wheel uses a Radio Frequency (RF) to transmit to the TPMS. I get the TPMS error sometimes when I drive by a local airport.

Both happening at the same time could be coincidence or some electrical issue that provides power to both.

I'm not a big believer in coincidences. I think the two problems were related. Whatever, when the TPMS or whatever went off the entire problem disappeared.

First the transmission issue. Then 25 miles later, The TPMS issue, checked the tires, OK, then it started blinking, then solid, then off. Then no further problems the remainder of the day and about 100 miles of driving. Just like it never happened.

I also wonder about that "clunk/boom" in the transmission whether it could have stressed a part and will cause trouble later on down the road even if this particular problem never recurs.

I've never had a single problem with this car until today. Just weird.

 

[missourimule]

One more thing to add. After I went back up the road to find the "pothole" I thought I had ran over, I pulled in to the side of the road backed up and when I put it into drive I had another powerful 'clunk/boom." Wonder what this meant. Again, the car is now driving perfectly. Questions, Questions.

 

[Goose]

That is indeed strange. As a fellow SX owner, I'm hopeful this issue was just a one-time glitch. Please let us know if your dealer replaces anything in the future to solve the problem.

Best of luck to you...

 

[missourimule]

That is indeed strange. As a fellow SX owner, I'm hopeful this issue was just a one-time glitch. Please let us know if your dealer replaces anything in the future to solve the problem.

Best of luck to you...

No more than me. Thank you for the kind words.

I called to the dealership and talked to the service manager as they are open from 10-2 on Saturday and explained my great concern. I told him that we are down to a one car family and if this stops in the middle of nowhere we are up the creek. He said that Kia would talk care of us and pay for the costs of a rental should it come to that. He was very cordial which is encouraging.

I've bought 20 or so new cars in my life and have never really had a serious problem. Frankly, I've never had any really serious problems with any car I have owned. So when this happened yesterday it was a real eye opener that there is always the first time.

This particular car has been otherwise exemplary. It handles great, acceptable fuel mileage and the layout and ergonomics are just perfect. I'm not in anyway concerned about the engine as I just don't think that will ever be a problem. The transmission was totally unexpected.

I did touch on the recall for the Sorento which involved a shaft that had to do with the four wheel feature (I think) and he said that was a totally different transmission. (A person can research this on the internet.) I can't trace this problem to the Forte. Usually, someone will complain and it will be almost a duplicate of what another experiences. I found a similar post in the Hyundai forum which I attempted to respond to but it also had a brief comment about the TPMS light coming on momentarily.

I think what I am going to do, somewhat reluctantly, is when the questionnaire comes to me I am going to tell that the service department treated me well, provided the information but that the problem is not now occurring. However, I will press the issue that I want to get to the bottom of this with a reasonable explanation. It may apply additional pressure by copying NHTSA and see what falls out. It is unlikely that I am the only person who has had this problem. I intend to see this through to a satisfactory conclusion. And Kia will be better off because the worst thing for an automobile company is to have unsatisfied customers.

I'll keep everyone posted. Thanks for your post.

 

[missourimule]

I decided to get to the bottom of this issue before I have to go back to the dealer again and be told there is nothing showing on the trouble codes. Clearly there had to be something wrong that needs correcting. What it is I don't know. I also don't like what might happens to a transmission that is stressed such as occurred the other day.

To assist those who may have similar problems or other problems, some tips follow.

1) When contacting KIA use Internet Explorer as Firefox doesn't bring up the subject in the inquiry form. It is easy to register, to send inquiries and they will respond with a confirmation code. That has been done and I should hear this week sometime.

2) As a follow-up I also made an inquiry to NTHSA copying them the e-mail I sent to KIA. As of this time I don't have a confirmation from them.

3) There is also a toll free number but the offices were closed this date. On the major corporate website it gives an e-mail which evidently is no longer operative as my e-mail bounced. So I was forced to use the "approved" form. Fortunately I finally guessed it might be the browser and was proven correct. I was about to pull out what little hair I have. I couldn't bring down the drop-down menu for "subject" in Firefox but it worked in IE. Just download the browser if you don't have it. Occasionally it comes in handy. Normally I just use Firefox which I am using now as it is like a well broken in pair of shoes. I don't get all this razzle dazzle that IE has.

As of this time, the transmission is operating perfectly but I want to nip this in the bud and get on top of this right now. If this transmission is defective in some way, I want it replaced with one that works properly 100% of the time. Clearly something is wrong. If anyone has had a similar occurrence I would strongly urge that KIA and NTHSA be contacted to get on file. It will also help in the event the normal drive line warranty runs out. You'll have proof on file and they won't be able to deny the claim.

This is also something anyone can sign up for and requires IE to work properly. Should have the service bulletins.

http://www.kiatechinfo.com/

I think post #2 explains this problem. It is a pressure problem inside the transmission. I've seen this on vehicles with many miles (100,000+ or more.) If I understand it correctly, the problem is inside the transmission (don't have a clue how electronics would be inside a transmission) but that is why the transmissions are being replaced in affected vehicles. I've done a lot of research on this problem today. Now the trick is getting KIA to deal with it as it is a design problem of a component that controls the line pressure in my humble view.

 

[Goose]

Thanks for the update. I hope Kia is responsive to your request. Wouldn't hold my breath waiting for NTHSA to respond...

You certainly have my sympathy regarding this issue. Like you, I haven't had any major problems with any of the many cars I've owned through the years. Something tells me that neither of us is tough on our cars.

Since cars are so well engineered and manufactured these days, problems such as your transmission hiccup are unacceptable on a new car. I'd be all over Kia like a wet blanket until the issue is repaired. The next time I'm at my "local" dealer (an hour and a half away), I'll ask if they're familiar with anything like this. Of course, I'll be sure to pass along anything I learn on the subject.

 

[missourimule]

Thanks for the update. I hope Kia is responsive to your request. Wouldn't hold my breath waiting for NTHSA to respond...

You certainly have my sympathy regarding this issue. Like you, I haven't had any major problems with any of the many cars I've owned through the years. Something tells me that neither of us is tough on our cars.

Since cars are so well engineered and manufactured these days, problems such as your transmission hiccup are unacceptable on a new car. I'd be all over Kia like a wet blanket until the issue is repaired. The next time I'm at my "local" dealer (an hour and a half away), I'll ask if they're familiar with anything like this. Of course, I'll be sure to pass along anything I learn on the subject.

Yes, please do.

I did get a reply from NTSHA today but it looks like they made a file on the inquiry and "closed" the case telling me that if I want to make a complaint to do such and such. I'm not holding my breath but at least I'm on record.

I haven't yet heard back directly from KIA. However, I went to the KIA dealership in Lufkin, Texas today and talked at length with the service manager and everything that I was told by the dealership in Tyler was essentially the same. However, he did look up to see if there were any bulletins of which there were none. He mentioned the Sorento issue and they have replaced one transmission of which they sell a lot. Sorentos are a hot item in this are of the country; Fortes less so.

I described the problem and he said that when the valve operated, it would behave as I have described but he did not believe that any damage would result. However, should this happen again, he will be happy to do any warranty work. This is a very nice dealership and is affiliated with the Hyundai dealership up the road in Nagadoches. He also echoed what I had been told by the Tyler dealer in that I should be provided a rental car on Kia's dime should it require repair. He said it would take from 3-5 days to repair, evidently including the transit time to get the transmission in stock and that the dealers do not repair these transmission; they replace them which corroborates everything I have read on this subject. Everything is located inside the transmission.

As of this time, I have had no problems with the car since this one incident last Friday and have driven it approximately 250 miles. If it happens again, then I'll have to cross that bridge when I come to it. In the event it blows up after the five year and 60,000 mile driveline warranty, I will have both the report to the selling dealer, the ticket and the report to NTHSA. There is no point in worrying about it. This explains and illustrates the transmission in question.

Compact 6-speed automatic transmission