Key fob suddenly stopped working

RABID_MP5

Member
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2002 Protege5
Basically it worked to open the car, then I drove and parked and it failed to lock it. No response at all. Range had been OK when it happened. The drivers door switch does still work OK. Where do I start? The battery is seated OK - I didn't hit or drop the fob right before this happened. I have a second good fob if I can find it.
 
It's super easy to pop it open and change the battery inside the fob. Its a watch battery that you can get pretty much anywhere. CR2025

 
Sounds like the battery is bad. Not a big deal. Mine went bad all of a sudden too.

After replacing the battery, you will need to program the fob. It won't work to unlock the car and disable the alarm system if you don't program. And because of Mazda's utterly moronic alarm system, you will not be able to start the car. It doesn't give 2 s**** if you have the key. However, in a bind, you could bump/push start it if it's a stick because the alarm only disables the starter circuit.

Instructions for Programming Key Fob
http://protege.jessecablek.com/2011/11/mazda-protege-5-fey-fob-programming.html

I recommend doing this with one of the windows rolled down. I wouldn't trust this crap box to not lock itself during the open/close door sequence. Or you could just press the door jamb button.
 
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.... However, in a bind, you could bump/push start it if it's a stick....

Apparently, we are NEVER supposed to bump start our car because even that is enough to destroy our pre-cat.... Go figure... (the unburnt gas thing...)
 
I never had to program the fob for my P5 or MSP when the battery died in them. I put in the new battery, unlocked the car and went for a drive. Did you have to reprogram yours, Maroon?


That's a trip about the precat thing too... I've push started my P5, my MSP, all my RX-7s and even my Miata once or twice with no issues.

Still passed smog.
 
Yes, I had to reprogram mine. Maybe yours wasn't quite as dead?

My precat is long gone - the guts anyway.

I wouldn't expect push starting to be much different than engine braking. But come to think of it, it is said that fuel injectors shut off when you engine brake or coast so why would push starting even work? Maybe below a certain rpm they turn back on?
 
Oreilly's/Autozone and most parts stores have a rack near the registers with a receiver on it that will tell you if your fob is working or not. They have batteries for them in the same place.
 
Yes, I had to reprogram mine. Maybe yours wasn't quite as dead?

My precat is long gone - the guts anyway.

I wouldn't expect push starting to be much different than engine braking. But come to think of it, it is said that fuel injectors shut off when you engine brake or coast so why would push starting even work? Maybe below a certain rpm they turn back on?

Well on the fob I found my spare & it works. A different (not new) battery in the bad one didn't, so have to figure it out.

On the injectors, you gotta have high manifold vacuum for them to shut off. Basically no vacuum when you pop start it.
 
Question about the key fob. I bought my cat without one. Any particular way I should go about getting one? And also programming it? Not to knowledgeable on these.
 
All P5s have keyless entry. Just obtain a fob from a junkyard, eBay, or various online vendors.

Refer to post #5 in this thread for programming.
 
That's a trip about the precat thing too... I've push started my P5, my MSP, all my RX-7s and even my Miata once or twice with no issues.

Well... It's only a caution, not a warning...

But tow starting sounds like a hell of a lot of fun!!!

I'm gonna go try that now...

I'll report back on injuries.

 
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It's reasonable for them to recommend against it. It is plausible that fuel would be dumped into the exhaust causing a back fire which could burn the cats.

But if there's no other option, I'd still do it. Mine started quick, and it was just being pushed at maybe 3 mph by 2 guys.
 
I suppose it's to cover their ass in the event that someone tries to roll start a car that has a problem aside from the starting system, filling the cats with fuel.

It's saved my bacon a few times too. My truck had a flaky starter at one point, and didn't want to start after getting some gas. I grabbed a hold of the door frame and got it rolling 5mph or so, hopped in and popped the clutch in 3rd. It fired right up. It was probably a sight to see for bystanders.
 
Hey if I have one fob that works, there's no way that I can lose it if I try programming the other and screw up, right?
 
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