2G How To: Wiring & logging a GM IAT sensor

This is a write up on how to wire in a GM IAT (intake air temp) sensor in a 2g and logging it using DSMLink V3. If you want to make the switch to run a SD (speed density) setup but aren't sure how to wire in your IAT your in the right place. Since you'll also need to connect a MAP sensor to go SD you'll also want to read Wiring & Logging a AEM 3.5bar MAP Sensor if you haven't already.

First you'll need to get a GM IAT sensor, harness, and a 3/8" NPT bung and have it welded into a UICP. ECMTuning sells it as a kit direct from their site, just click on this link. GM IAT sensor w/pigtail and 3/8 bung

INSTALLATION

1. Once you get the bung welded onto your UICP thread the sensor into it and tighten it down with a wrench, then mock up the wiring harness.
   
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2. After mocking up the sensors pigtail unplug it from the back of the connector and trim the insulation off the ends of the wiring.
   
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3. Find the MAF connector and expose the wires going into the back of the connector so you can clearly see them.
   
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4. Find the BLACK sensor ground wire and the RED/BLUE intake air temperature sensor wire going into the back of the MAF plug and cut them.
   
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5. After you cut them pull them out of the wire loom so you've got room to work with, then strip the insulation off the ends.
   
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6. Attach a butt connector on the ends of the spliced wires and crimp them.
   
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7. The GM IAT pigtail wires aren't signal specific so it doesn't matter which one you splice into the sensor ground or IAT wires. Just put the ends of them in the butt connectors and crimp them.
   
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8. After you wrap the exposed wires and butt connections up with electrical tape zip tie it up tight and plug it into the sensor.
   
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LOGGING

1. After you connect to DSMLink go to your ECU Config (live) button.
   
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2. Then click the ECU Inputs tab.
   
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3. If you haven't already you'll want to select the box that Locks your intake temperature and baro. Since you wired in the GM IAT into the OEM intake air temp. sensor wire you'll want to select the drop down menu from the Intake Temp pin assignment.
   
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4. Now scroll down the list of sensors and find the GM IAT and select it.
   
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5. Once you do that you'll want to click the Save pin assignments button.
   
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6. Hit F10 and find GMIAT in your Captured Values menu and double click it.
   
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7. Hit F12 and start a data log, then hit F9 while its logging and select GM IAT from your Displayed Values menu.
   
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8. Go back to your log, now see if your GM IAT sensor is logging like it should be.
   
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Happy Boosting and if you have any questions feel free to shoot me a PM.

 

[steve]

I assume in this How To, you're actually running Speed Density since you also have a MAP on the MDP. I don't know why one might only want to connect and log a GM IAT sensor when using a MAF but if you did locking the Baro without a MAP sensor might cause some issue.

From Dave @ ECMTuning:

Just about the only time that it's desirable to check that checkbox is when you are running a MAF translator. If you've selected Speed Density or a GM MAF sensor as your base MAF, IAT and Baro are implicitly locked, no need to check the checkbox (although it doesn't hurt).

Dave

If you select a GM MAF sensor or Speed Density as your base MAF, the ECU implicitly locks IAT and Baro. No need to check the checkbox. Checking the checkbox is only needed when using a MAF Translator, and because the Translator provides its own, albeit sometimes inaccurate, locked IAT and Baro settings, checking the checkbox is really only needed when running a MAF Translator and you are applying and aftermarket-sensor signal to the IAT or Baro inputs.

Dave