The powertrain control module (PCM) continuously monitors that the system voltage stays within the proper range. If the PCM detects an excessively high system voltage, DTC P0563 will set. A high voltage condition may cause a stalling condition or other driveability concerns.
| • | The engine run time is more than 20 seconds. | 
| • | Engine running above 1200 RPM. | 
| • | Vehicle speed above 8 km/h (5 mph). | 
| • | The PCM senses the system voltage is above 19 volts. | 
| • | All of the conditions are present for 5 seconds. | 
| • | The PCM stores DTC P0563 in the PCM memory when the diagnostic runs and fails. | 
| • | The PCM will record the operating conditions at the time the diagnostic fails. The PCM stores this information in Failure Records. | 
| • | The PCM disables most outputs. | 
| • | The transmission defaults to a predetermined gear. | 
| • | The torque converter clutch (TCC) operation is inhibited. | 
| • | The instrument panel cluster (IPC) displays a message. | 
| • | The malfunction indicator lamp (MIL) will not illuminate. | 
| • | The Conditions for Setting the DTC are no longer present. | 
| • | A history DTC will clear after 40 malfunction free ignition cycles. | 
| • | The Powertrain Control Module (PCM) receives the clear code command from the scan tool. | 
Step  | Action  | Value(s)  | Yes  | No  | 
|---|---|---|---|---|
Schematic Reference: Starting and Charging Schematics Connector End View Reference: Engine Electrical Connector End Views  | ||||
1  | Did you perform the Engine Electrical Diagnostic System Check?  | --  | Go to Step 2  | |
 Is the battery voltage less than the specified value?  | 19 V  | Go to Step 4  | Go to Step 3  | |
3  | Replace the generator. Refer to Generator Replacement . Is the action complete?  | --  | --  | |
4  | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 4.2L. Did you compete the replacement?  | --  | Go to Step 5  | --  | 
5  | 
 Does the DTC reset?  | --  | Go to Step 2  | System OK  |