Circuit/System Description
WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) has 2 internal 5-volt reference circuits. Each internal reference circuit provides external 5-volt reference circuits to more than one sensor. A short to ground or short to voltage on one external 5-volt reference circuit can affect all the components connected to the same internal 5 V reference circuit.