The ECM provides ground to one side of the coil of the main relay and the other side is connected to the battery. The ECM monitors battery voltage and the voltage after the main relay.
If ECM detects malfunction in power supply system, ECM sets DTC P0560.
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal check
Poor connection
Open / Short
Main relay
Case1
Enable
Conditions
Time after engine start >120 sec
Vehicle speed > 10 kph
Threshold Value
Voltage > 22.0V
Case2
Engine stall
Voltage < 0.47V
Diagnostic Time
0.2 sec
MIL ON Condition
NO