IAT sensor

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dt,

I see, after the better part of 2 days, you haven't received a single reply. Perhaps others, like myself, have NO idea what the IAT sensor is. Could you clarify?

I'm thinking "Intake Air Temperature" but don't want to assume anything. :D

 
Anyone have any values off this sensor (beyond that in the manual)?

Thanks
Wow! This thread is really old with no answer to the original question. I only found it on a search because I was wondering the same thing. Maybe I'm lazy, but I hate to remove the sensor and heat it in a pot of water to 176F to check the resistance.

Perhaps someone out there has checked their's at ambient temp and could give me the temp and resistance reading.

I am not sure how to remove it from the airbox. Is it threaded into the box or is there a nut on the inside of the box? The manual either doesn't have this info or is hiding it from me.

I know someone out there has torn their airbox down far enough to Know the answer to this question.

Thanks,

John

 
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Mine measures 3.77k at 52F but I don't know if it is good or not.

I suspect it may be bad because of very poor running when ambients drop below 45F.

 
"Poor running below 45." Is that on initial cold start, or after it warms up? If it's only while the engine is cold, it has nothing to do with the intake air temp. If it's after warmup as well, there's still about 57 other things that would be more a likely issue, i think.

 
If you use you FSM and go to the sensor operation or diagnostic code number 5 in the bikes gages , that will display the temp that the IAT is reading. If the engine is cold (not run for a day) then just compare that to the actual air temp, it should be close.

 
If you use you FSM and go to the sensor operation or diagnostic code number 5 in the bikes gages , that will display the temp that the IAT is reading. If the engine is cold (not run for a day) then just compare that to the actual air temp, it should be close.
Not familiar with FSM.

Is that the diagnostic mode on page 8-69 of the shop manual?

Is it necessary to disconnect the fuel pump?

 
"Poor running below 45." Is that on initial cold start, or after it warms up? If it's only while the engine is cold, it has nothing to do with the intake air temp. If it's after warmup as well, there's still about 57 other things that would be more a likely issue, i think.
After warm up.

If it's 50 degrees down here in the valley I can ride around with no problem but if I head up the hill outside of town where the temp drops 15 degrees, it still runs good as long as you don't stop. Once you stop the idle is rough and the bike won't take gas without stalling. The only way to get it moving is with a big handful of throttle and slipping the clutch. This is particularly exciting if you are on a gravel parking area.

Come back down the hill to warmer temps and it runs fine again.

I thought it might be an altitude thing but it does the same thing down here in the valley at temps in low 40's.

 
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If you use you FSM and go to the sensor operation or diagnostic code number 5 in the bikes gages , that will display the temp that the IAT is reading. If the engine is cold (not run for a day) then just compare that to the actual air temp, it should be close.
Not familiar with FSM.

Is that the diagnostic mode on page 8-69 of the shop manual?

Is it necessary to disconnect the fuel pump?
FSM = Factory Service Manual, or using your nomenclature, Factory SHOP Manual. Same thing.

 
...Is that the diagnostic mode on page 8-69 of the shop manual?
Is it necessary to disconnect the fuel pump?
You are looking for the Sensor Operation Table which is on page 8-53 in my manual.

You do not have to disconnect the fuel pump. In the FSM read the section starting with:

DIAGNOSTIC MODE

Setting The Diagnostic Mode

The FSM (Page 8-49) will instruct you to use the ignition key and the Select and Reset buttons on the Meter Assembly to enter the Diagnostic Mode where you will be able to run the rest of the test for the IAT without running the engine. The value display is metric so bring your ºC to ºF converter with you. I have a How-To here which will tell you what the displays are on the Meter Assembly.

 
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Thanks for all the good info from everyone.

I did manage to access the diagnostics and the temp value on my gen II showed up in Fahrenheit.

As best I could tell it was reading 5-6 degrees warmer than ambient. I don't know if this is within specs but I suspect it is.

Since it is 53 in my garage right now,which is not the temp where I am having the problem, I think I will roll it outside early tomorrow morning and check it with the ambient in the 30's.

All the other diagnostics looked good.

 
...temp value on my gen II showed up in Fahrenheit....As best I could tell it was reading 5-6 degrees warmer than ambient...it is 53 in my garage...
Either that or the IAT sensor is indeed in ºC and your defective IAT sensor thinks it's 140º F. I can only speak for Gen I which shows everything in the MKS system. The FSM always shows prime metric measurements first and the USA values in parenthesis after.

We need a Gen II (and maybe a Gen III) person to verify that your FJR really reads in ºF. It is unusual for this kind of sensor to go bad. I will note that my Gen I is selectable between km and miles whereas the Gen II isn't. Dunno if that may be related.

Edit to add: The reading in F/C is just a math thing and computers are good at that. Usually when the base software is set out (like in 2001 World bikes) the software engineers don't go back in and mess with core code, they build on what is already written and proven. What you are reading in the diAG mode is what the ECU is using for inputs so if it has indeed changed to ºF some engineer was busy for not much gain.

 
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I'm pretty sure the diag readout for a Gen II (USA) FJR is in °F. It was one of the things I looked at when I had some issues a couple of years ago.

 
I agree about the sensor being unlikely to go bad, but in the section on testing the sensor they warn you to handle it carefully and if it is dropped it should be replaced. I'm guessing it might therefore be susceptible to vibration or shock.

 
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