Temperature gauge (ambient) abberation?

[Unobtanium]

Mine reads 5*F hotter than actual, consistently. Day or night. Is the pick-up for this thing located in the engine bay or is there a way I can properly calibrate it and it just needs dialing in, or what? All of the past vehicles I have had with temp read-outs are +- 1*F from actual.

 

[arunka007]

Same here. Have the same problem.

The gauge worked fine in previous cars, so this is kind of a step backward in a newer car.


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[GP 2004]

Ditto. I will follow this to see what solution is posted.

 

[mazdadude]

The AMBIENT Air Temp sensor is traditionally found behind the grill, directly in front of the radiator.

This same 5 degrees of separation is found on other models of the Mazda line, and also complained about on other Mazda forums.

I doubt you could calibrate it, but if we did some research, and knew some specs, I am certain we could put a proper resistor inline and get the reading a little more accurate.

 

[Unobtanium]

The AMBIENT Air Temp sensor is traditionally found behind the grill, directly in front of the radiator.

This same 5 degrees of separation is found on other models of the Mazda line, and also complained about on other Mazda forums.

I doubt you could calibrate it, but if we did some research, and knew some specs, I am certain we could put a proper resistor inline and get the reading a little more accurate.

Thanks for the data. I will just move on, and know that I need to subtract 5*F. I had come to rely on this feature in all of my other vehicles because when it hit about 34-38*F, I could count on ice on some bridges, and it also gave me good feed-back of when my tires were going to be not so effective, etc. once I got to learn the compound I was on.

 

[arunka007]

I observed the reading is close to accurate when starting the car. It starts reading higher when the engine warms up.

Wondering how other cars get it right though. Are their sensors located elsewhere?

 

[Unobtanium]

I observed the reading is close to accurate when starting the car. It starts reading higher when the engine warms up.

Wondering how other cars get it right though. Are their sensors located elsewhere?

I have kept an eye on this for a long time, now, before mentioning it. Start-up temps are not any more accurate in my case. It was in the 90's the other day, and I cranked the car and it was reading well over 100*F. I never had this issue with ANY other car, and it's shocking that Mazda has this problem. I don't know where the pick-ups were for any vehicle I've owned as I never cared because they always got it right. This is the first I've dug into it. It's not a big deal of course, but I was curious, and now I know.

 

[piotrek91]

I have kept an eye on this for a long time, now, before mentioning it. Start-up temps are not any more accurate in my case. It was in the 90's the other day, and I cranked the car and it was reading well over 100*F. I never had this issue with ANY other car, and it's shocking that Mazda has this problem. I don't know where the pick-ups were for any vehicle I've owned as I never cared because they always got it right. This is the first I've dug into it. It's not a big deal of course, but I was curious, and now I know.

All your other cars must have been magical! They got their EPA rated MPG at 80 and always read the correct temperature!

Every single car I have ever been in has this problem. The local temperature in a parking lot is usually going to higher than the "official" temperature of the area. Even if you're parked in the shade and especially if your car is still warm from a previous drive.

Having said that, once my car is driven at speed I find that my temperature reading is usually withing 2 degrees of most outdoor temperature displays (banks ect.)
If your car is still off by 5 degrees when your car is being driven at speed than your temperature reading definitely performs worse than mine.

Here's what the temp sensor reads according to the service manual. I think the two lines might be the possible range of readings? If so, than the margin of error is very large and could definitely explain your 5 degree offset. The sensor is located behind the front bumper and as mazdadude said, you could definitely connect a resistor in series with it and fix your offset. I would recommend using a variable resistor so you can calibrate it on the fly after you've attached it.

 

[arunka007]

I have kept an eye on this for a long time, now, before mentioning it. Start-up temps are not any more accurate in my case. It was in the 90's the other day, and I cranked the car and it was reading well over 100*F. I never had this issue with ANY other car, and it's shocking that Mazda has this problem. I don't know where the pick-ups were for any vehicle I've owned as I never cared because they always got it right. This is the first I've dug into it. It's not a big deal of course, but I was curious, and now I know.

Do you park in a garage or out in the sun? I almost always have a covered parking and that might be the reason for closer-to-accurate (still higher than accurate) temperature while starting the car.

These days it's always showing me 104-107 after few minutes of driving when its 95-98 outside.

Previous cars had accurate readings in the same conditions.

 

[Unobtanium]

All your other cars must have been magical! They got their EPA rated MPG at 80 and always read the correct temperature!
THey performed as advertised. What can I say?
Every single car I have ever been in has this problem. The local temperature in a parking lot is usually going to higher than the "official" temperature of the area. Even if you're parked in the shade and especially if your car is still warm from a previous drive.
What cars have you been in? Corvette, 370Z, Jeep were the last 3 I had.
Having said that, once my car is driven at speed I find that my temperature reading is usually withing 2 degrees of most outdoor temperature displays (banks ect.)
If your car is still off by 5 degrees when your car is being driven at speed than your temperature reading definitely performs worse than mine.

Here's what the temp sensor reads according to the service manual. I think the two lines might be the possible range of readings? If so, than the margin of error is very large and could definitely explain your 5 degree offset. The sensor is located behind the front bumper and as mazdadude said, you could definitely connect a resistor in series with it and fix your offset. I would recommend using a variable resistor so you can calibrate it on the fly after you've attached it.

Interesting. I will observe it at speed. It was a cool night last night and I was 5*F higher than the bank sign, and so I checked my phone/weather station, and it agreed with the bank's sign.

 

[Unobtanium]

Do you park in a garage or out in the sun? I almost always have a covered parking and that might be the reason for closer-to-accurate (still higher than accurate) temperature while starting the car.

These days it's always showing me 104-107 after few minutes of driving when its 95-98 outside.

Previous cars had accurate readings in the same conditions.

My last observation was taken at 0200hrs last night.

 

[yrwei52]

Here's what the temp sensor reads according to the service manual. I think the two lines might be the possible range of readings? If so, than the margin of error is very large and could definitely explain your 5 degree offset. The sensor is located behind the front bumper and as mazdadude said, you could definitely connect a resistor in series with it and fix your offset. I would recommend using a variable resistor so you can calibrate it on the fly after you've attached it.

I can see the location of ambient temperature sensor on CX-5 could be problematic as it's right in front of AC condenser and radiator. The same sensor on our VW and BMW, although behind front bumper, all located very low near the belly-pan and away from condenser and radiator.

 

[V8toilet]

Mine reads more true after it's been driven for a mile or so and the radiant heat from the radiator isn't effecting it or the heat rising from the hot asphalt. I'm surprised you guys aren't aware of these effects on the sensor.

 

[Unobtanium]

Mine reads more true after it's been driven for a mile or so and the radiant heat from the radiator isn't effecting it or the heat rising from the hot asphalt. I'm surprised you guys aren't aware of these effects on the sensor.

Now that I know where it is, it makes sense. Dodge, chevy, and Nissan put their sensors in smarter places and this is the first I've seen it.

 

[MikeM.]

All your other cars must have been magical! They got their EPA rated MPG at 80 and always read the correct temperature!

That's really something! (bs)

Every single car I have ever been in has this problem. The local temperature in a parking lot is usually going to higher than the "official" temperature of the area. Even if you're parked in the shade and especially if your car is still warm from a previous drive.

I've had a lot of thermometers in my life and the curious thing I've noticed is they tend to measure a combination of the air temperature and the objects around them. Put them in the sun and they go sky high. Put them near a hot engine and they measure the heat radiated from the engine. Who woulda thunk? (shrug)

Having said that, once my car is driven at speed I find that my temperature reading is usually withing 2 degrees of most outdoor temperature displays (banks ect.)

The thermometers in banks in my area vary by up to a 8 degree range on a hot day. I can drive by 3 of them in 4 minutes. It's rare that they all read within 3-4 degrees. My CX-5 is all over the place too during hot days depending on how hot the asphalt under the car is, whether it was parked in sun or shade and which way the car is facing relative to the sun. This is to be expected. When the temperatures get in the 30's and I'm not driving in heavy or stop-n-go traffic, it settles right down and does the job it's supposed to (warn of potential ice).

Of course roadway ice can form when the temperature is well above 32 degrees under certain atmospheric conditions so temperature is just a general guideline.

The sensor is located behind the front bumper and as mazdadude said, you could definitely connect a resistor in series with it and fix your offset. I would recommend using a variable resistor so you can calibrate it on the fly after you've attached it.

Variable resisters can vary depending upon temperature and are not as stable as most fixed resisters. If the thermometer really does need calibrating, it might be better to use trial/error using a selection of fixed resisters. But it's never going to be perfect due to the effects mentioned above. Well, unless you have a magical car. (whistle)

 

[arunka007]

Now that I know where it is, it makes sense. Dodge, chevy, and Nissan put their sensors in smarter places and this is the first I've seen it.

This is my main gripe with Mazda. Other manufacturers have recognized this problem and installed their sensors in smarter locations. As mentioned in an earlier post, I never had this problem with a 2008 Honda, of all makes!

 

[MikeM.]

This is my main gripe with Mazda. Other manufacturers have recognized this problem and installed their sensors in smarter locations. As mentioned in an earlier post, I never had this problem with a 2008 Honda, of all makes!

Wow! You should be on Mazda's promotional/advertising payroll if your main gripe with Mazda is the location of the ambient air temperature sensor!

 

[Unobtanium]

That's really something! (bs)
So, tell me more about what you know about my personal experiences? (It typically averaged around 17.5-18.5, but coming back from New Orleans, it did exceptionally well).

I've had a lot of thermometers in my life and the curious thing I've noticed is they tend to measure a combination of the air temperature and the objects around them. Put them in the sun and they go sky high. Put them near a hot engine and they measure the heat radiated from the engine. Who woulda thunk? (shrug)
Indeed, indeed. Somehow my Nissan and Jeep always nailed it, though. The Corvette was always garaged, so I can't much fairly say. If I wasn't driving it, it was in the garage.



The thermometers in banks in my area vary by up to a 8 degree range on a hot day. I can drive by 3 of them in 4 minutes. It's rare that they all read within 3-4 degrees. My CX-5 is all over the place too during hot days depending on how hot the asphalt under the car is, whether it was parked in sun or shade and which way the car is facing relative to the sun. This is to be expected. When the temperatures get in the 30's and I'm not driving in heavy or stop-n-go traffic, it settles right down and does the job it's supposed to (warn of potential ice).
Crazy that it varies so much on the CX-5. Never experienced that. I have double-checked with weather.com when I see bank signs though, and I drive almost exclusively at night, so I don't think sunlight/shade is the issue.

Of course roadway ice can form when the temperature is well above 32 degrees under certain atmospheric conditions so temperature is just a general guideline.
For sure! About 34*F is when I reliably saw it on bridges where I used to live.


Variable resisters can vary depending upon temperature and are not as stable as most fixed resisters. If the thermometer really does need calibrating, it might be better to use trial/error using a selection of fixed resisters. But it's never going to be perfect due to the effects mentioned above. Well, unless you have a magical car. (whistle)

I'm not going to mess with it. Sorry you have issues with believing that some cars actually DO perform as advertised. What's interesting is that when I posted my MPG results on the various forums, that was about what everyone else was seeing, as well. Some saw 1-2mpg more, some saw less, but most said that's exactly what they got under similar circumstances. Of course, herd mentality is far from scientific, but it seems good enough for this forum, so I'll go ahead and cite it, lol

 

[Unobtanium]

Wow! You should be on Mazda's promotional/advertising payroll if your main gripe with Mazda is the location of the ambient air temperature sensor!

You're just as skewed. I mean, you wax eloquent about "balance" and "handling" and how you like the base motor because it strips a bit of weight off the nose and makes the vehicle much more responsive like it's some sort of sports car, and then anytime someone brings up "I would like a little more power" we get the "IT'S AN ECONO SUV! IT HAS PLENTY OF POWER!". I mean, that's funny right there.

I believe what he MEANT was that Mazda persists with things like that in his opinion: Refusing to perform little "value added" fixes that everyone else has tended to. At least, that's how I took it to be.

 

[arunka007]

Wow! You should be on Mazda's promotional/advertising payroll if your main gripe with Mazda is the location of the ambient air temperature sensor!

Cool it dude.

What I meant here was that other cars do not have this problem from past 7 years onwards. I have personal experience of that with mine and my wife's cars.

It seems to be a simple/logical fix and I don't like it that Mazda hasn't addressed it in 2016. If u lack the intelligence to understand and has the attitude to only criticize, then that's your problem.

Ever wondered why many people here ignore your thoughts/observations? This is why.