I know I'm pushing gravedigging on this a bit, but just for anyone out there with this same issue: I had this exact thing, check engine light coming on and off, and o/d light flashing, but the car would "warm up" and begin to operate normally after 2 minutes or so. I replaced the speed sensor just like Mazdaspeedchick, it is really easy to do, just a single bolt, and its just beneath the air intake hose on the engine. As soon as it was in, the car was far more responsive in general, where before it took a second to respond to the gas pedal. Of course, the main issue of being stuck in a low gear was fixed as well.

 

The flashing OD light is the transmission fault check light. Same idea as the engine check light.

 

Hi Mazda Protege5 people!

Okay, my Transmission is slipping into 2nd/3rd gear and the O/D light is blinking as well. I think this "downshifting" symptom is a safety measure brought on by the fact that the Pulse Generator is failing. My cheap OBII is not pulling any codes.

I also found a video online that basically shows my issue (although, my P5 is an automatic with ABS). The youtube link is below:

UPDATE AFTER REPLACING THE PULSE GENERATOR:
- I was NOT able to resolve the above issue by replacing the Pulse Generator. This is the term used in the repair manual for the part I replaced today: FN0121550 (Automatic with ABS part number).
- The car will NOT go into Reverse now and it makes a loud clunk when I shut the engine off.
- The O/D light stopped flashing but that's probably because I didn't drive it long enough.

- For my own knowledge, are these terms equal to "Pulse Generator"?
1.) Speed Sensor (ISS)
2.) Turbine Speed Sensor
3.) Input Speed Sensor
4.) Throttle Position Sensor
5.) Crankshaft Position Sensor
- I've seen these terms tossed out there and according to the P5 manual, the part I'm dealing with is only called a Pulse Generator.
- I've fully confirmed that the Pulse Generator part # is FN0121550 and if you put this number into Amazon.com, you'll get Beck/Arnley 090-5047--WHICH IS INCORRECT. I ordered 090-5047 and it's a three-prong and absolutely not the Pulse Generator FN0121550.
- I removed the air intake system and NOT the battery + tray. From there, it was pretty easy to get to. CAVEAT: Be careful not to get any dirt in the sensor hole/insert.


Also, I have 266K miles and think it's probably time to change the transmission fluid. Or is it?

- Is this okay to do on a car this old? Someone told me that the car has "developed" its own tranny fluid viscosity/consistency and that fresh/new transmission fluid could completely send it to hell. Is that true? Sounds odd but logical, too.

Please address my questions.

Thank you.
N

 

Hi, I had this last year on my Tribute auto V6. ended up with a bill for £1,000 for a recon gear box. 4 of the rings in the gear box were broken

 

Hi there.
Replacing the pulse generator did not work. It won't even go into reverse now. Off to the transmission shop I go.
Thanks for your post.
N

 

In case it matters, the out-the-door price with 8.75% CA (city) tax is $4550.00, inclusive of the following work:
1.) A "new" transmission (rebuild was not possible) parts and labor, with a 36-month/100,000 mile warranty. Planetary gears melted down due to low or no lubrication flow. This was causing the car not to go into Reverse and into Safe Mode. "New" one will have updated specs.
2.) Timing belt AND Water pump - parts and labor
3.) Rear ABS speed sensor - part only
4.) Crankshaft seal - parts only
5.) Three engine mounts - parts only (There are six total and only three were busted)

Well, I could go buy a used car for the 4300 dollars and the 4500 dollars I spent on the car (between last year and this year) but who knows what kind of problems I'd inherit...including the ones I ALREADY resolved on my P5. I had a new catalytic converter installed last year and now I'll have a "new" trans.

I do wish I had the time and knowhow to pull an old one myself...but at least I'm getting a super great warranty here and won't break my back.

Thanks to everyone who participated. I'll keep you in the loop just in case another poor soul has these issues come up and can benefit from my experience here! :-)

N