keethrax
keethrax Dork
1/13/17 11:25 a.m.

So, throwing a P0096 code in the '08 Mazdaspeed3. Which looks like IAT sensor 2.

My first reaction was: Maybe it's just too damn cold and so it's out of range (temps being in the -40 degree range). Cleared it on a warmer (relatively speaking, low single digits above zero) day, but it came back.

Unless I am missing something, the error implies two sensors. Presumably one is the one built into the MAF which I am assuming is #1 if they are numbered in the order the air hits them. The other? I am assuming closer to the intake on the motor because where else would it be... But it's back to being really cold out there and I don't want to spend too much time freezing my fingers off in exploration mode. This needs to be as quick an in and out procedure as I can manage.

My first step is just going to be check connections and possibly give them a cleaning, but where is sensor #2.

Anyone know how that error is determined? If it's based on a mismatch comparing it with #1 somehow could the issue be there instead?

Thanks in advance.

keethrax
keethrax Dork
1/13/17 11:35 a.m.

Also, if there is a second sensor I don't see it for sale at the first few online spots I checked...

Hopsonn
Hopsonn New Reader
1/13/17 11:37 a.m.

I haven't had this code come up in my own car, but I found a post on mazdaspeedforums claiming it was related to a bad MAP sensor which probably has an integrated air temp sensor.

Good luck.

keethrax
keethrax Dork
1/13/17 11:40 a.m.
Hopsonn wrote: I haven't had this code come up in my own car, but I found a post on mazdaspeedforums claiming it was related to a bad MAP sensor which probably has an integrated air temp sensor. Good luck.

Didn't (for some reason) consider two different integrated temp sensors. Was for some reason picturing a second IAT near the MAP. So thanks, that'll help speed things along and keep frostbite at bay.

NEALSMO
NEALSMO UltraDork
1/13/17 12:38 p.m.

Confirmed second IAT sensor is in the MAP.

Knurled
Knurled GRM+ Memberand MegaDork
1/13/17 12:40 p.m.

They also generally correlate air temp sensors with coolant temp sensors when starting the car, they should be within 5 degrees or so after a certain number of hours.

The0retical
The0retical Dork
1/13/17 12:47 p.m.

Yea the map sensor is the secondary measurement on that car.

Are you running the stock MAP sensor, a Bosch with a pigtail, or a PnP one?

If it's the Corksport PnP they sent out a new one to address some issues that v1 had.

keethrax
keethrax Dork
1/13/17 12:57 p.m.
The0retical wrote: Yea the map sensor is the secondary measurement on that car. Are you running the stock MAP sensor, a Bosch with a pigtail, or a PnP one? If it's the Corksport PnP they sent out a new one to address some issues that v1 had.

Stock.

keethrax
keethrax Dork
1/13/17 12:58 p.m.
Knurled wrote: They also generally correlate air temp sensors with coolant temp sensors when starting the car, they should be within 5 degrees or so after a certain number of hours.

After a certain number of hours off? As in the ambient temp should agree once they've had time to settle?

The0retical
The0retical Dork
1/13/17 1:22 p.m.

Let me know if you need another stock MAP sensor. I've got one laying on my workbench.

keethrax
keethrax Dork
1/13/17 1:36 p.m.
The0retical wrote: Let me know if you need another stock MAP sensor. I've got one laying on my workbench.

Thanks, I'll let you know ASAP.

alfadriver
alfadriver MegaDork
1/13/17 1:48 p.m.
keethrax wrote:
Knurled wrote: They also generally correlate air temp sensors with coolant temp sensors when starting the car, they should be within 5 degrees or so after a certain number of hours.
After a certain number of hours off? As in the ambient temp should agree once they've had time to settle?

As soon as you start running, they won't be the same- the second sensor is downstream of the turbo- so it's measuring both air temp and boost pressure to adjust the fuel and spark. Since it's a MAF car, mostly the spark to prevent knock.

keethrax
keethrax Dork
1/13/17 2:36 p.m.
alfadriver wrote:
keethrax wrote:
Knurled wrote: They also generally correlate air temp sensors with coolant temp sensors when starting the car, they should be within 5 degrees or so after a certain number of hours.
After a certain number of hours off? As in the ambient temp should agree once they've had time to settle?
As soon as you start running, they won't be the same- the second sensor is downstream of the turbo- so it's measuring both air temp and boost pressure to adjust the fuel and spark. Since it's a MAF car, mostly the spark to prevent knock.

I should have phrased that better. I meant:

Right after it starts, but after it has been sitting for a while so the sensors should be seeing ambient and can 'compare notes'?

Just trying to see if I understood what he was saying.

alfadriver
alfadriver MegaDork
1/13/17 4:52 p.m.

In reply to keethrax:

No. Which is what I'm trying to say...

The only time they are close are after it being off for 8 hours or so. Once it starts, they go apart pretty quickly.

More than likely, the it's a broken sensor, not drift.

keethrax
keethrax Dork
1/13/17 8:11 p.m.
alfadriver wrote: In reply to keethrax: No. Which is what I'm trying to say... The only time they are close are after it being off for 8 hours or so. Once it starts, they go apart pretty quickly. More than likely, the it's a broken sensor, not drift.

I guess I still worded that badly, but whatever. I don't mean after it's been running at all. I have to imagine that temp diverges pretty quick, and turbo can't help intercooled or not. Pretty much meant a quick blip when you turn they key after it's been sitting. Are you saying it actually checks while just sitting there?

I should have said right when you turn the key to start. That's what my brain was thinking. But it's clearly not what I wrote. ;P

And yeah, broken sensor is my inclination but none available locally so going to check connections and such just in case before attempting to acquire a new one. Would hate to get a new one and find out a connector was loose, something happened to short a wire, something was all gunked up or similar.

alfadriver
alfadriver MegaDork
1/13/17 8:21 p.m.

Actually, the temp sensors are so good that they generally don't check each other.... Just giving you crap.

Which is another way to say that your idea to check the wiring before the sensor is a really good idea.

The sensor you are working on usually are good....

keethrax
keethrax Dork
1/13/17 8:28 p.m.
alfadriver wrote: Which is another way to say that your idea to check the wiring before the sensor is a really good idea.

Well it's more of a "If it's an obvious wiring/plug issue I can fix it tomorrow, otherwise it'll take more time" than an actual plan. There are downsides to living in the middle of nowhere.

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