The battery supplies electricity to the ECM even when the ignition switch is in the OFF position. This power allows the ECM to store data such as DTC history, freeze frame data and fuel trim values. If the battery voltage falls below a minimum level, the memory is cleared and the ECM determines that there is a malfunction in the power supply circuit. When the engine is next started, the ECM illuminates the MIL and sets the DTC.


DTC Detection Conditions

Trouble Areas


Open in ECM back up power source circuit (1 trip detection logic)

• Open in back up power source circuit

Battery terminals

If DTC P0560 is set, the ECM does not store other DTCs or the data stored in the ECM are partly erased. MONITOR STRATEGY

Related DTCs

P0560: ECM system voltage

Required Sensors/Components (Main)


Required Sensors/Components (Related)


Frequency of Operation



3 seconds

MIL Operation

Immediate (MIL illuminated after next engine start)

Sequence of Operation


Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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