Most Accessory Sensors dont work

[Shay07]

I recently bought a beautiful 2008 Mazda 3 GT, has 65,000 km on it. What I didn't find out until later is that none of my AUTO settings work. My Rain sensing wiper don't work on AUTO, my AUTO lights don't sense that it is dark out either. I have heard from other owners that their average gas consumption is always 10.4 and the average speed calculated is always 38 km. Even if I'm doing 110 km on the highway. These numbers have never changed, so I think those sensors are faulty as well.

Any recommendations on how to repair these sensors???? I don't even know where to start. Its not covered under warranty anymore.

[SonicBoy]

For the gas mileage, have you considered resetting them back to zero when you refuel?

For the auto wipers, have you tried the sensitivity settings?

For the auto lights, they don't come on at all at night? Perhaps someone did some modifications for HIDs or independant Fog Light mods.

Was this car bought used? Has this been happening from day one?

[bluemazda3]

some more info is needed!

[TheMAN]

he said it's recently bought... how more obvious does it need to be that he bought it used?

the best thing he can do is go to the dealer and pay them to diagnose the problems... it's very likely it's not the sensors that's bad but a computer or wiring... stuff that happens when some idiot (previous owner) screws around with the electrical system

[peterm15]

Fuse?

[Noisy Crow]

For the fuel economy........ does the "instant" mode show the fuel consumption changing?
For the rain & and auto light sensors..... can we assume that you have the switches in the "auto position"? In any case, they both use the same sensor module, which is located on windshield underneath the mirror. If you pull the map light down (push sideways to release some pressure on the clip and pull down at the same time) you can check that that sensor is plugged in correctly. You can also pull the cover off of the rain sensor and check that things are plugged in properly there as well, but the rain sensor cover is a pain to remove if you don't exactly where to press/pry etc.

[DualSoul]

Shot in the dark, but possible windshield was replaced sans sensor?

[Noisy Crow]

Shot in the dark, but possible windshield was replaced sans sensor?

That could be. It's permanently affixed to the windshield, so does bump up the cost of replacing it...........

[Shay07]

Wow thanks for the good places to start looking. I DID buy it used.. I bought it about 3 weeks ago, during the day and it was sunny ( no rain)!!! I do have the switches in the correct positions, and have looked at my car manual to confirm ( just In case). The auto wipers have never moved, not even a budge, but settings 1 and 2 work fine.
The auto lights, do not turn on at night at all, they dim the interior lights, on the dash, stereo, steering wheel and only the daytime running lights are on.

For the gas mileage comment from sonicboy, the gas mileage is fine, it tells me when I fuel up that I have 600 something km til empty and I have tracked that it is counting down correctly no problems there... The issue Im having is the average calculation for speed (38km) and average fuel consumption (10.4) they never change.. I wonder why I should know the average at all, if they never change?


ThEMAN- This is exactly what my mazda dealer told me to do, and I will, but before I pay them out my ass for a disgnosis I wanted to make sure it wasnt something small that I can handle doing myself.


NoisyCrow, yes the instant fuel economy calculator does change, it will jump from 12.8 to 6.0 or even to 0.0 if I am coasting, it definitly works fine.

In regards to the actual sensor, I googled the rain sensor and it showed me a rearview mirror with extra functionality. I was under the impression that the sensor was a black piece on my windshield( Im not sure how to explain that in better words) but then I find that it may be part of my rearview mirror. I may have just confused myself more, can someone explain this a little better.... thanks.

"You can also pull the cover off of the rain sensor and check that things are plugged in properly there as well, but the rain sensor cover is a pain to remove if you don't exactly where to press/pry etc."-Noisy Crow- I dont think I have this.....

Thanks everyone, I look forward to your advise again.
Shaylene

[Zuluwun]

For the Avg Fuel/Speed, just reset it. The longer it runs without resetting, the less it'll change because it calculates an average. The fact that your Instant Fuel consumption is working correctly means that the sensor is fine. (To reset Avg Fuel consumption, make sure you're at that screen - hit INFO till you get there, then hold down INFO for about 3 sec till it indicates --)

Same reset procedure for avg speed. I never really bother with avg speed, I get the impression that as long as the engine is on, the computer's calculating an average speed meaning that when you're stopped/idling that goes into the calculation as well.

oh, and googling anything about a mazda 3 will usually get you a TM3 hit, so try searching the forum. I remember seeing a how to for an auto-dimming mirror or something that had some good pics of the rain sensor

[Shay07]

Thanks Zuluwun,I will try to reset it as soon as I get back in the car, I didnt know you could reset it.

This is my second day on the mazda forum and cant believe how helpful this has been....

[Noisy Crow]

Rain sensor is attached to the windshield. It is not part of the rearview mirror. There should be a black box stuck to the windshield, behind the mirror. The black box is the cover/trim plate the hides the actual rain sensor and its wires.

[Skippy]

Does the car have HID Lights? As far as I know, the auto feature isn't compatible with HID's

[Iceman_F1]

The auto wipers have never moved, not even a budge, but settings 1 and 2 work fine.
The auto lights, do not turn on at night at all, they dim the interior lights, on the dash, stereo, steering wheel and only the daytime running lights are on.

EDIT: Never mind this first bit. I didn't realize mazda actually called them setting 1 & 2.

As for the auto lights, your statement that I quoted is a bit confusing. You say they don't turn on at night but they dim the interior lights, on the dash, steering wheel. If you mean that they light up at night but not the actual headlights, it might not be a sensor problem and like TheMAN said, might have been something done by the previous owner. But if dash lights and everything are coming on (you can tell by the green headlight symbol on the gauge cluster) at night but not the headlights themselves, I'd look there and not the sensor.

Me personally though, I'd rather turn them on myself instead of relying on the car to figure out when to do them. This is specially true to those who set it to auto and forget about it for the lights as, in bad weather, it sometimes doesn't trigger the headlights but it's bad enough that you need the lights on.

Sorry for being picky about minor details and hopefully you get it figured out.

Does the car have HID Lights? As far as I know, the auto feature isn't compatible with HID's

Auto lights work with stock HID but if it was aftermarket HID, then that would be something the previous owner did and what TheMAN was talking about. In which case, it's still not the sensor itself but someone screwing with the wires to disable or bypass the sensor/computer.