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 below 2.54V during 0.2 sec, ECM sets DTC P0561.
Item
Detecting Condition
Possible Cause
DTC Strategy
Input signal check
Poor connection
Open/short to ground in control circuit
Charging system
Main relay
Enable Conditions
-
Threshold Value
Voltage < 2.54 V
Diagnostic Time
0.2 sec
MIL ON Condition
3 driving cycle