GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Generic 🢒 1999 🢒 Unit Repair 🢒 Engine 🢒 Engine Controls - 6.5L 🢒 DTC P0560 System Voltage

Refer to .

Circuit Description

The PCM continuously monitors the system voltage. The system voltage information is taken from the PCMs ignition feed circuits. Since voltages below 8.0 volts or above 17.1 volts, could cause improper system operation and/or component damage. Class 2 Serial Data is shut down when system voltage is below 9.2 volts or above 16.0 volts. A scan tool will not display data if system voltage is outside this range. Because of this, use a DVM in order to monitor system voltage when checking to see if the fault is currently present.

Conditions for Running the DTC
  1. The engine speed is greater than 672 RPM.
  2. The vehicle speed is greater than 9 MPH (15 Kph).
  3. The engine run time is greater than 600 seconds.

Conditions for Setting the DTC
  1. The PCM senses system voltage below 10.0 Volts.
  2. All diagnostic set conditions met for 2 seconds.

Action Taken When the DTC Sets
    • The PCM stores DTC P0560 in memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The PCM will record the operating conditions at the time the diagnostic fails. The PCM stores this information in Failure Records.

Conditions for Clearing the MIL/DTC
    • A History DTC will clear after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
    • Use of a scan tool.

Diagnostic Aids

Important: Remove any debris from the PCM module connector surfaces before servicing the PCM module. Inspect the PCM module connector gaskets when diagnosing/replacing the module. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM module.

Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed.