LTG swap IAT issues

[rattbastard13]

Putting an LTG in a buggy Im building and cant get it to fire. Have spark and fuel rail pressure. The only issue I can find is my IATs are all over the place! On my OBD2 scanner with ambient air temp around 60 deg. b1s1 is reading 95 deg, b1s2 is reading 90 deg, b1s3 is reading 208 deg! if I swap out the boost/IAT sensor on the charge pipe b1s3 is 148 deg. Compared the IAT tables on my HP Tuners to a stock tune I got off the forums and the are exactly the same. When I heat up the boost/IAT sensor the temp on b1s3 drops and if I cool it off it goes up! Anybody have an idea where to start looking? Thx

[tunerpro]

What trouble codes are setting? Maybe your OBD2 scanner isn't interpreting the data correctly.

Have you disabled VATS and done a write entire? That would explain why it won't fire.

[rattbastard13]

The only codes that come up are. P0315, P0237, P2227. the ECM and harness was done by Swap specialties (unfortunately). Did a write entire last night, made no difference. IAT on VCM scanner is reading 92 deg., cant figure out how to read the different IAT sensors.

[tunerpro]

P0237 is a turbo charger boost sensor circuit low. As an aside, this is the SAME sensor that provides the IAT3 reading. I would check to make sure you have proper ground, power, etc. at that sensor

P2227 may be setting because of P0237. When you key up the ECM, it checks to make sure MAP, BARO, and Boost sensor all match. The BARO sensor is part of the MAF sensor assembly.

P0315 is crankshaft angle not learned. Not relevant for this issue.

[rattbastard13]

So, think I may have found it. The iat/boost sensors are wired backwards. MAF sensor is wired into the boost side on the ECM and vice versa. According to these pin outs I found. Pre throttle should be the boost side and turbo intake pressure should be the maf, correct?

[tunerpro]

The MAF sensor should have IAT1, IAT2, BARO, and MAF wired to it. The integrated boost sensor, also known as the TIAP (throttle inlet absolute pressure) sensor has IAT3 and boost pressure sensor.

[rattbastard13]

Thats whats throwing me off! if I unplug the MAF sensor IAT1 and IAT2 both read -40. But, 2 different wiring diagrams are saying its going to the wrong spots on the ECM.

[rattbastard13]

according to this diagram, my iat/boost sensor on the pressure side is going to where the maf should

https://cardiagn.com/2013-cadillac-a...mance-circuit/