I'm trying to help out a friend with a '97 Protege LX, 1.5L. Lately her transmission will shift out of O/D, flash the O/D light, and throw the CEL...it's very intermittant, however. I believe her CEL was previously being triggered anyways (probably the P1195 code), and she had it looked at and was told it wasn't an important problem (the car was running fine at the time). She took the car to a mechanic yesterday and also had the OBD codes read at autozone and got P0715 & P1195. The mechanic wants to replace the input turbine speed sensor (relating to P0715), but also noted that her fluid is in horrible condition and that he wasn't entirely sure that replacing the speed sensor would solve the issue (the trans might be beyond help). He wants about $400 to replace the sensor and do the fluid/filter change. I'd like to save her money and do these things myself - at least the fluid/filter change.

I read that this is a common problem - is it generally the sensor itself or the wiring?
Does anyone know the part number for the input turbine speed sensor? Is it externally mounted? Can the resistance be tested to verify functionality? Price? Online source?

I also know there is a common problem with the trans temp sensor wiring being damaged and causing similar symptoms, but no code is popping up for that specific problem.

Any help is greatly appreciated! Thank you

 

Ok, Matt. Let's break this into the "3" problems you have.
1. The biggest is the transmission fluid. You probably have never changed the fluid, which would cause you to have some have problems with the overdrive gear, because you are in that gear the most. The overdrive gear could be worn. I will quote from the 1996 Mazda Protege shop manual. Look at the fluid and make a determination accordingly.

a. Clear Red = Normal
b.Dark, Muddy, Varnished or strange smelling = Powertrain components damaged.
c. Light pink = Water in AT fluid
d. Reddish Brown = Deteriorated AT fluid.

I would not do the fluid myself. The reason is that most tranny shops do a deep flush that really pulls all the fluid from the valve body. Check with your mechanic and see if he has the machine to do this.

2. Input/Turbine speed sensor - It isn't all that hard to get to, it is under the battery tray, on the top of the transmission. ButI don't think it is cheap. I did a quick search online and did not find that part. From the 1996 shop manual, The resistance should be 200-400 OHM. You might want to call the dealer and see what it costs. I bet about $150. Most boneyards will not pull a sensor off a good transmission. If you want to see what it is to change, email me and I will scan the page from my 1996 shop manual.It should be the same.

All in all, I think your mechanic is being very fair in the $400 range.

3. The P1195 code is an EGR Boost sensor. Look further back in this forum. BabyHuey helped someone else with some real good advice.. It worked for me too. Here is a link https://www.mazdaforum.com/m_36162/mpage_2/key_/tm.htm The only difference is after I did all the steps, I still got the code. I ended up going to the boneyard and gettingboth the EGR boost Sensor and the EGR solenoid. It is the other part that the vacuum goes through when it comes from the manifold, it is on the same bracket. You should be able to find this at a boneyard, mine didn't even charge me for it. If you have to pull it yourself, bring WD40, Mazda used aluminum bolts to stick it to the firewall and they tend to seize up. The sensor and solenoid do not come off the bracket easy, and if you crack the boost sensor case, it will not work because it has to hold vacuum.

 

Thanks for the advice on perhaps picking up some parts at the salvage yard, I'll look my local yards tomorrow. I wasn't kidding when I said it is a friend's, and money is tight, but you're right - she has likely not changed the fluid since she got the car in 2000. We're not even in the same state (flying out to see her), so I can't give you my own opinion on the fluid condition at this time. At the same time, I've flushed (pumped) my own transmission myself and could do it with hers as well. I actually found a mazda service guide so I guess I've answered some of my original questions at this point, but thanks also for the EGR info.

 

OE part number for the Turbine speed sensor is fw01-21-550. Dealer retail of $82.05 or available at
www.onlinemazdaparts.com for $65.64 so is not that expensive. Only occuring intermittent could be poor electrical connection related as well so make sure to check that as well.
There is also something to be said for the trans fluid temp sensor as you noted. Faulty sensor will not necessarily set a code if the reading is still within an expected parameter. Below a certain fluid temperature the trans computer is designed to block out overdrive to speed the warming of the trans oil. If the sensor is sending a 185'F signal and then suddenly signal drops to -10'F the computer will block out overdrive and will shift trans down to 3rd gear. Logically one would think that a code would be set when this happens but the computer is not logical and just sees that the temperature is either within a normal parameter or not. Say this from experience has had to chase down that exact problem many years ago on an older MPV that had already been to 6 other shops for the problem.

 

babyhuey - thanks, I wish I had rechecked this thread half an hour ago. I found the part number, but it was a lot of work Thanks for the link where I can order it, though. I'm going to order it to have on hand at the least and if I don't need it I'll put it on ebay or something, or save it for a rainy day.

Thanks again, I'll be sure to check the wiring as well.