Possible causes

– Battery defective
– Loose or missing alternator drive belt
– Faulty alternator
– Open or short system voltage circuit

Tech notes

Higher than expected voltage problems are most likely caused by bad voltage regulator. The voltage regulator is part of the alternator.

When is the code detected?

he voltage supply at the Engine Control Module (ECM) is greater than 16.5 volts for at least 5 seconds.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0563 JEEP Description

The battery supplies electricity to the Engine Control Module (ECM) even when the ignition switch is OFF. This electricity allows the ECM to store data such as Detected Trouble Code (DTC) history, freeze frame data, fuel trim values and other data. If the battery voltage falls below a minimum level, the ECM will conclude that there is a fault in the power supply circuit. The next time the engine starts, the ECM will turn on the Malfunction Indicator Light (MIL) and a DTC will be set.