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.
During engine running, if system voltage is below 11V, ECM sets P0562. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item
Detecting Condition
Possible cause
DTC Strategy
Voltage too low
Poor connection
Open in circuit
Faulty charging system
Faulty main relay
Faulty ECM
Enable Conditions
Engine works
Threshold value
System voltage < 11V
Diagnosis Time
Continuous
MIL On Condition
2 driving cycles
Coil Resistance
70? ~ 120?