GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 DeVille 🢒 Engine 🢒 Engine Electrical 🢒 DTC P0563

Circuit Description

The powertrain control module (PCM) checks the system voltage to make sure that the voltage stays within the proper range. Damage to components, and incorrect input can occur when the voltage is out of range. The PCM monitors the system voltage over an extended length of time. If the PCM detects an excessively high system voltage, DTC P0563 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0563 System Voltage High

Conditions for Running the DTC
    • Engine speed above 1,500 RPM.
    • System voltage between 9.5-18 volts.

Conditions for Setting the DTC

The PCM detects a system voltage above 16 volts for less than 1 second.

Action Taken When the DTC Sets
    • The PCM will command a message to be displayed.
    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will store conditions which were present when the DTC set as Fail Records data only.

Conditions for Clearing the DTC
    • The PCM will command the message OFF after one trip in which the diagnostic test has been run and passed.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear DTC Information function.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics in Engine Controls - 4.6L

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. Start the engine.
  3. Raise the engine speed above 1,500 RPM.
  4. With a scan tool, observe the Ignition 1 Signal parameter in the powertrain control module (PCM) data list .

Does the scan tool indicate that the Ignition 1 Signal parameter is less than the specified range?

16.0 V

Go to Step 4

Go to Step 3

3

Using a scan tool compare the Battery Voltage parameter in the DIM data list with the Ignition 1 Signal parameter in the powertrain control module (PCM) data list.

Is the Battery Voltage and Ignition 1 Signal parameter readings different by more than the value specified?

0.8 V

Go to Step 4

Go to Charging System Test

4

Replace the PCM. Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

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Go to Step 5

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5
  1. Review and record the scan tool Fail Records data.
  2. Use the scan tool in order to clear the DTC.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
  4. Using the scan tool, observe the Specific DTC Information for DTC P0563 until the test runs.

Does the scan tool indicate that DTC P0563 failed this ignition?

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Go to Step 2

System OK