PO715-Input/Turbine Speed Sensor Circuit Malfunction-97 Ford Taurus

Check you actual voltage when it is running and also check the O2 sensor. If it hasn't been replaced good chance that it is failing without sending a code yet. If you have a low voltage while running or poor ground to the engine you will have various problems like this also. If the CAT hasn't been replaced yet there is another possible source of problems.

Chris

Chris,

Thanks for your reply. So are you saying that the O2 sensor could be the culprit? Should I still replace the MAF & Turbine speed sensor? I have been told that my check engine light may have been tampered with. The last time I had to go for inspection for emissions, the diverter valves code came up, again with no check engine light coming on. I replaced both diverter valves and that worked. Does the readiness check for the OBD shed any light on the problem? The printout from the inspection showed the following as NOT READY. Overall Rediness, Catalytic Converters, Evaporative System, Secondary Air Injection, Oxygen Sensors, Oxygen Sensor Heaters, EGR System. As far as I know the CAT has never been replaced. I was thinking of going to a transmission shop but don't want to be taken for a ride, (pardon the pun) and told I need a new transmission if it is just a simple fix. I am a female (Mitch is my nickname) and have to do alot of research on the problem so I don't get taken advantage of by some repair shops. I have a mechanic that I trust but he does pretty basic repairs only so depending on the problem he sometimes can't help me.

Thanks,

Mitch

Just read that my vehicle has 4 O2 sensors, 2 upstream & 2 downstream. I'm guessing that it would be the 2 upstream sensors that I should replace if necessary?? Also is the Turbine Speed Sensor the same as a VSS? I'm trying to price them online and come up with nothing when I type in Turbine Speed Sensor. I have seen VSS sensors but they look like they would have more to do with the odometer speed cable and not the transmission. Can anyone tell me where the Turbine Speed Sensor is located? I have the Hayes Repair Manual but it is very vague on the Turbine Speed Sensor.

Thanks again,

Mitch

Hey Mitch!!

I can't help you with your immediate problem, but I would recommend that you burn your Hayes book. They reach the point that they tell you nothing about everything. Chiltons is a little bit better, but the best bet is to get a shop manual from the manufacturer (FORD). They ARE more expensive than the others, but they are for your year and model ONLY, and have everything you need. I never regretted the money I spent on one for my Honda Accord. I drove that thing for dang near 20 years, and it had 250,000 miles on it when I donated it to Kidney Car (and it still ran).

Bill

Thanks Bill,

Good advice. I will save my Haynes Manual for when I get a bird or a puppy and then put it to good use. I had an 86 Pontiac Grand Prix that I had a good manual for and I got 253,000 out of it. Everyone kept telling me V6 engines were crap and they didn't last. The only reason I had to get rid of it was because body rot. The motor was still sound. They don't make em like they used too. They were so easy to work on yourself, less sensors and computers controlling them, just the idiot behind the wheel.

Mitch

Mitch, can you tell me where the heck is the Input / Turbine speed sensor located on a 99 Ford Taurus. Is it the same as the VSS?

Regards,

Phil

Phil,

From the research that I did, I don't think they are the same. To me it looked the VSS (Vehicle Speed Sensor) has more to do with the odometer cable. The Turbine Speed Sensor can only be purchased from the dealer and cannot be returned. I purchased one but me and my mechanic could not find where it was located. I still have the part kicking around somewhere. My best advice to you would be to go to a website called www.JustAnswer.com. They have Ford expert mechanics that will answer your questions and even send diagrams. You have to register on the site, and give your credit card info. You ask your question and post what you are willing to pay for the answer. Usually between $9.00 to $15.00. You choose the best answer. You may have more than one response. I have used this site a few times and have gotten some good advice and helped me solve the problem myself. Great for the do it yourselfer. It has saved me hundreds of dollars.

I hope this helps.

Good Luck!!

Mitch

you have to take the front drivers side wheel off and you can get at it it's right above the cv joint to the left, easy to get out a pain to put back in. it has an 8mm bolt. it's easier to disconnect the wires after you get it out. good luck.

This has already been fixed here on CR4 I believe, go to the RH side of the screen and fin "Search all of CR4" with "Turbine Speed Sensor". Then just read through the three blogs concerned with this problem.

It appears to be common......

Thanks Andy,

I read a couple when I first found this site. I just read through all of them and now I know where to find the sensor and how to check it. I called Ford and it cost $33. I just have to find the ID tag on the bell housing because my car has 1 of 2 different transmissions which is not specified in the VIN#.

No problem, I hope that the replacement works as it should for you, please let us know either way.

Its certainly a cheap fix and should allow you to get a much better price for the car when you sell it than at present!

Have a great day.

I'll let you know if it works. I also found a cheap fix for the MAF sensor that I think I'll try. I found it on another site from a guy that deals specifically with Ford products. He said to try it for the PO171 & PO174 codes that I have. It says to disconnect the MAF sensor connector. If the lean driveability symptoms go away the MAF sensor is probably contaminated. If the symptoms do not go away then the MAF is probably not contaminated. Rather than replace the sensor, go to your local Radio Shack and get a can of spray tuner cleaner, #64-4315. Disconnect the NEGATIVE battery cable and remove the MAF from the vehicle. Spray inside of the MAF with the tuner cleaner being careful when you spray the hot wire. Clean it well and let dry for 15 to 20 minutes. Do not use carburator or brake cleaner because they leave a residue. The tuner cleaner dries residue free. When the MAF is dry put it back in the vehicle and reconnect the NEGATIVE battery cable. Drive the vehicle several miles to let the PCM "relearn" your specific driving conditions. Once that is done the codes will not come back and you should notice all the symptoms are gone as well. (I hope). It's worth a try before spending $$$ on the sensor. I'll let you know if this works as well.

Mitch

I had that sensor go on my VW Diesel some years ago when driving in the Italian Alps with a heavy caravan in tow!!! I lost probably half of my BHP!!! It is very noticeable with a Diesel engine....VW Cars affected were built on or since 2001.

I probably took off half the clutch material doing hill starts in the mountains at 4,500 RPM, and slipping the clutch like crazy!!! But due to a vibration problem some months later, they had to put a new clutch in anyway.....probably because of what I had done!!

All under guarantee of course......

MAF = Mass Air Flow. The part has several names depending upon who you ask!!!

Some VW owners have replaced the sensor with one from Mercedes (all sensors made by the same company! Just housing is different. They are sold on ebay for this purpose) as it was cheaper and easily available, whereas the VW version was at that time in short supply and expensive (without Guarantee of course!!). It gave the VWs a tremendous boost in BHP, exactly how much I do not remember, as the characteristics were for a different engine/control system......it was a favourite VW Diesel tuning for quite some time!!!

Anyone who wants to learn more about this sensor can click this link:-

http://www.carbasics.co.uk/what_is_an_air_mass_meter.htm

Well, this is really strange. I bought the Turbine Speed Sensor and cleaned the MAF Sensor. My mechanic and I looked for the Speed Sensor on top of the touque converter where the ford schematic said it should be and found nothing that looked like the sensor I got from Ford. The sensor is "L" shaped and has two prongs on one end and is round with a metal contact in the center on the other end and has a metal piece attached to the side with a bolt hole. The end with the metal contact looks like it would plug into a hole. We looked all over and the only thing we found on the converter housing was a white plug which had 9 prongs. We could not tell if the bottom part came out. I did not replace the speed sensor. All I did was spray the contacts with the tuner cleaner and plug it back in. I went to the inspection station and 3 out of the 4 codes were gone. PO171, PO174, PO715. The speed sensor code and the lean fuel bank 1&2. The PO102 MAF sensor circuit low input code was still there. I went to the junkyard, got a MAF, cleaned and installed it, went back to the inspection station and the PO102 code was gone and now it is reading the PO171 & PO174 codes again. WTH!!! The inspection guy cleared the codes out and said to drive around 2-3 days and come back. The transmission is no longer banging into gear once the engine is warm. It does stall sometimes when you shift into reverse but it starts right back up. I've been running injector cleaner and it seems to be surging less and running a little smoother. I did forget to put the gasket on the MAF (DUH). I realized it as I was driving home from the inspection station. I'll fix that tomorrow but now I'm scratching my head. I guess the oxygen sensors could be the problem. There is no rattle or rotten egg smell so I'm hoping the CAT is still good. I'll let you know what happens. Tune in tomorrow for the next episode of "As the stomach turns"

MItch

Interesting Post, thanks....

We all like to see that someone like you gets everything fixed up good, you appear to be on the right road and almost there....

Replaced the MAF gasket, drove the car around over the weekend, went back to insp. station today and the PO171 & PO174 codes are gone and the PO102 is back. Did alot of forum searching and a few hours of reading everything pertaining to Code PO102 and it looks like it is a poor or loose connection or ground wire circuit. I looked closely at the wires leading the the MAF and didn't see anything that looked bad. I suspect maybe a loose wire in the connector plug or a corroded contact. The PO102 code wasn't there after I replaced the MAF. The PO171 & PO172 codes were back because there was a vacuum leak because I had forgot to put the gasket on. After I put the gasket on those codes went away and the PO102 code is back. What are the chances of 2 MAFs being bad?? I'm going to take a better look at it tomorrow and try to get a voltmeter to test the 4 wires in the MAF plug. I am now wondering if my orginal MAF is still good and the code showed up because of a loose or bad connection in the plug. I also read that it could be the fuse under the hood in the power distribution box. What a pain this is!!!!! I am so close to figuring this out.

please do not give up!! Support yourself with the probable fact that the dealer would have taken as long to get where you are using his hourly rate and your pocket book, so even if you eventually have to get the final fix maybe from him, you will have saved yourself a 3 to 4 figure sum in the meantime!!! Good work.

I won't give up. Failure is not an option. I agree with you about the dealer thing. If I had taken this to a dealer I would have already spent close to $700 or $800 by now. Besides, not only am I saving money, I am getting an education in auto repair for pretty much no cost except for my time which I feel is well spent. I can't sleep because I can't wait to get to the car and figure this out.

Top notch!! Keep us up to date between fixes please....

"By George I Think I've Finally Got It" Upon taking a closer look at the wires I unwrapped the electrical tape nearest the distributor and "Voila", the red power wire is broken and frayed. I went to the auto parts store to get some wire and when I told the guy what I needed it for he told me to put back the wire I was going to buy and he had a piece of wire which he gave me for FREE!! I'm going have some lunch and then go out and fix it. I'll let you know how I do. Next time, I will be more thorough in checking all the wires FIRST before I go replacing parts. Live and Learn. I did another post in the electrical section for instructions to fix this properly. I'll keep you posted!!

This is better than most TV programs, and no murders!!!