GM IAT not reading: 04 MSM, Rev MS2E - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 03-04-2017, 07:21 PM   #1  
Xio
Newb
Thread Starter
 
Join Date: Mar 2016
Posts: 7
Total Cats: 0
Question GM IAT not reading: 04 MSM, Rev MS2E

I am slowly working on install and tuning of a Reverant MS2E in my 04 MSM, and I am having issues with the GM IAT sensor. I've wired the GM IAT into the wires for the stock pre-throttle body sensor (IAT2), and setup the GM sensor in Calibrate Thermistors per instructions, but it reads a constant 80 degrees F in Tunerstudio, regardless of actual temperature.

Everything else with the install has gone well so far. ID725's, TPS, base timing, startup, idle tuning, even some Autotune at low speeds in the neighborhood... all good.

To troubleshoot the problem, I've performed these actions:
- wired in the old stock sensor. It too reads a constant value, regardless of settings in Calibrate Thermistor or actual temperature.
- used a heat gun to try and get either sensor to respond. No dice.
- measured voltage across the wires (with either sensor in place and key on), and from each wire to an engine bay ground... all measurements read basically zero (some noise up to 0.15V)
- checked continuity on both wires (from engine bay back to the pin in the connector that plugs into the ECU, pins 4O and 4R)... both read 0.3-0.5 ohms, so should be good?

It appears to me that I am not getting a signal to the IAT at all. Are there other tests I should perform? Could this be an issue with the ECU?

Other thoughts:
- I did move the harness where the IAT2 wires are (a bit) when I installed the ID725's. However, I don't think I moved it enough to break a wire...
- The IAT2 ground (black/red) is a shared with several other sensors (CLT for example). All these sensors function correctly in TS.

All help is appreciated, as I am fairly certain I need this sensor to function in TS if I wanna get this car running right.
Xio is offline   Reply With Quote
Old 03-19-2017, 03:42 PM   #2  
Xio
Newb
Thread Starter
 
Join Date: Mar 2016
Posts: 7
Total Cats: 0
Default

Bump. Anyone?
Xio is offline   Reply With Quote
Old 03-19-2017, 07:17 PM   #3  
Senior Member
iTrader: (1)
 
Join Date: Feb 2015
Posts: 810
Total Cats: 105
Default

Looks like you need a pull up resistor to 5v, 2.49k Ohm I believe. You can add this in the wiring loom or preferably in the ECM case, quite a few input channels have a spot on the board to add the pull up resistor.
Bronson M is offline   Reply With Quote
Old 06-06-2017, 12:08 PM   #4  
Junior Member
iTrader: (1)
 
Join Date: Mar 2013
Location: Traverse City, Michigan
Posts: 138
Total Cats: 4
Default

you ever get any resolve to this?? I have the same issue
ReallyRottenTurbo is offline   Reply With Quote
Old 06-06-2017, 10:17 PM   #5  
Xio
Newb
Thread Starter
 
Join Date: Mar 2016
Posts: 7
Total Cats: 0
Default

Quote:
Originally Posted by ReallyRottenTurbo View Post
you ever get any resolve to this?? I have the same issue
Yes, got it sorted after contacting Reverant. I'll reply in your thread.
Xio is offline   Reply With Quote
 
 
Reply


Tags
gm iat, mazdaspeed, ms2e, msm

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:08 PM.




We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.