The purpose of the System Voltage is to detect an excessively low or high system voltage that may be caused by a malfunctioning charging system.System Voltage is the ignition voltage potential at the Powertrain Control Module (ECM)ECM measures and compares voltage from ignition key and each relay. With this mechanism, ECM knows if the main relay switch turns on after IG on or if turns OFF after IG off.
If the system voltage is over 17 V during 0.2 sec, ECM sets DTC P0563.
Item
Detecting Condition
Possible Cause
DTC Strategy
Voltage check, high
Poor connection
Charging system
Main relay
Enable Conditions
Time after engine start > 120 sec
Vehicle speed > 10 kph
Threshold Value
Voltage > 17 V
Diagnostic Time
0.2 sec
MIL ON Condition
3 driving cycle