GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Savana 🢒 Engine 🢒 Engine Electrical 🢒 DTC P0563

Circuit Description

The engine control module (ECM)/powertrain control module (PCM) continuously monitors that the system voltage stays within the proper range. If the ECM/PCM detects an excessively high system voltage, DTC P0563 will set. A high voltage condition may cause a stalling condition or other driveability concerns.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0563 System Voltage High

Conditions for Running the DTC
    • The engine run time is more than 20 seconds.
    • The engine is running above 1,200 RPM.
    • The vehicle speed is above 8 km/h (5 mph).

Conditions for Setting the DTC
    • The ECM/PCM senses the system voltage is above 19 volts.
    • All of the conditions are present for 5 seconds.

Action Taken When the DTC Sets
    • The ECM/PCM stores DTC P0563 in the PCM memory when the diagnostic runs and fails.
    • The ECM/PCM will record the operating conditions at the time the diagnostic fails. The ECM/PCM stores this information in Failure Records.
    • The ECM/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.

Conditions for Clearing the DTC
    • The Conditions for Setting the DTC are no longer present.
    • A history DTC will clear after 40 malfunction-free ignition cycles.

Step

Action

Values

Yes

No

Schematic Reference: Starting and Charging Schematics

Connector End View Reference: Engine Electrical Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn OFF all the accessories.
  2. Measure the battery voltage at the battery using the DMM .
  3. Operate the engine speed above 2,000 RPM.

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?

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Go to Step 5

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4

Replace the engine control module (ECM)/powertrain control module (PCM). Refer to Control Module References for replacement, setup, and programming.

Is the action complete?

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Go to Step 5

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5
  1. Select the DTC option and the Clear DTC Information option using the scan tool.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the DTC reset?

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Go to Step 2

System OK