Hey Guys

i have an MSPNP2 with the diyautotune IAT sensor wired into the AFM wires as per instructions.

Recently i've noticed the wideband reading very rich seemingly randomly. i plugged into the laptop and saw my IAT reading were all over the place from -20 to +20 Celsius.

I rewired it last night and did a log from cold today.

It seems like the temperature reading are weird all the way up until the CLT is above 82 Celsius.

i've attached two logs. the first one is from cold and the second is when the CLT starts to rise above 80.

Note i work in Celsius not Fahrenheit!

Any thoughts? i have no idea how long this has been happening..

 

Also, the outside temp this morning was 15 Celcius

 

did you reboot?


serious: did you check your wiring from AIT back to MS?

 

Seems lke you have a bad connection in the sensor wiring.

An open circuit will show up as extreme cold, for instance.
I'd hook up the laptop and do a wiggle test with the engine running.

 

No i didn't. i'll check it after work a report back.

I tried this, and couldn't get it to change. i'll try again at the ecu wires and report back

 

Checking the connections at the sensor, especially inside the sensor plug will be very useful.

Also, a lot of temp sensors degrade internally.

 

it only has couple thousand miles done though, if even that!

 

a disconnected sensor should show 70°F so 20°C...

 

ok. it was showing 21 Celsius before i rewired the connections, so that's something.

ill do another log tonight if i have no luck checking the wiring to try and find a pattern

 

ok, no luck yet...

im wondering about the way its wired

ive wired it as below



But i was looking at the MS pinout guide and it says pin 10 is an IAT sensor input. would it ok to wire it directly to this instead of the way i have it currently wired?



It says input 10 is the IAT input

 

no.

 

What is that input for?

 

an AIT.

 

Can you or someone else elaborate? An AIT or IAT?

 

same thing different acronyms.


I'm assuming you had diy build your MS. They would have wired the AIT correctly to match your model year and have the AIT/AIT/MAT sensor come in on stock wiring. Apparently they also wire it so you could bring it in on the db15.

 

Ill keep looking for a reason behind the funmy readings then. The sensor reads 70f which you said means disconnected? But every so often it reads - figures and rarely it reads seemingly correct figures.

I found an ecu pinout diagram, so ill check and see what voltages it reads and the temp its reading and report back.

 

not voltage, resistance.

this screams loose vagina connections.

 

Ive cut and spliced the wires from the sensor into the loom so its definitely not that. Ill investigate at the ecu after work in a few hours.

Could the sensor just be a bad one? I have a feeling it never worked correctly

 

it's possible. I've seen a dud once, the element was just dangling.

 

So first things first

Ill check the resistance between the two sensor wires, and note what the outside temp is.

Then ill check the resistance between the two wires that are for the afm at the ecu pins?

Then visually check the sensor