Our GM MAF cable provides breakout points for the Baro and IAT inputs to the ECU. The image below illustrates the layout.
Note that cables manufactured after 8/8/2016 use a violet wire for +5v on the Baro pigtail in place of the previously used pink wire.
BARO NOTES: The signal wire for the Baro input (white wire) is a buffered input. For more information on what a buffered input means, refer to this page. To summarize, a buffered input reduces the electrical load of the connected sensor while providing a high current drive to the ECU input. This allows you to connect a variety of aftermarket sensors to an ECU input that they may not otherwise be able to drive directly.
IAT NOTES: The IAT wire is a passthrough to the ECU input. Unlike the Baro input, we can not provide a buffered input on the IAT because we must know the exact pull up and pull down resistor combination used for this input in order to accurately calculate temperature from the connected thermistor. This input is the ONLY input you can use to connect an aftermarket IAT sensor (like the GM IAT or AEM IAT) for use with ECMLink.
When wiring an IAT to the GM MAF cable breakout point, you will only need to use the ground and signal wires. The +5v power wire will not be used in this case and should be cut short and properly insulated to avoid the potential for an electrical short.