Circuit Description
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) monitors the main relay switched voltage on 3 parallel circuits that travel between the underhood fuse block and the ECM. These circuits are tied together internally in the ECM. When ignition voltage is present at the ignition 1 input to the ECM, the ECM will command the main relay ON by grounding the control circuit of the Main Relay. The ECM monitors the voltage over an extended length of time. If the ECM detects a voltage outside an expected range for the calibrated length of time, DTC P0560 will set.