GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The powertrain control module (PCM) monitors the system voltage to make sure that the voltage stays within the proper range. Damage to components, and incorrect data 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 a system voltage outside an expected range for the calibrated length of time, DTC P0560 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0560 System Voltage

Conditions for Running the DTC

    • System voltage below 9 volts or above 16 volts
    • Engine speed above 650 RPM
    • Vehicle speed below 40 km/h (25 mph)

Conditions for Setting the DTC

The PCM detects a system voltage out of range for 30 seconds.

Action Taken When the DTC Sets

    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will command a message to be displayed.
    • The PCM will store conditions which were present when the DTC set as Failure 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

Yes

No

Schematic Reference: Engine Controls Schematics .

Connector End View Reference: Powertrain Control Module 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. Install a scan tool.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
  3. Using the scan tool, observe the Specific DTC Information for DTC P0560 until the test runs.

Does the scan tool indicate that DTC P0560 has passed this ignition cycle?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. 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 within the specified range?

9-16 V

Go to Step 7

Go to Step 4

4

Using a scan tool, compare the battery voltage with the Ignition 1 Signal parameter in the PCM data list.

Is the battery voltage and PCM Ignition 1 readings different by more than the value specified?

0.5 V

Go to Step 5

Go to Charging System Test

5

Test the battery positive voltage circuit of the PCM for a high resistance or open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 8

Go to Step 6

6

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 8

Go to Step 7

7

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Is the action complete?

--

Go to Step 8

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8

  1. Review and record the scan tool Failure 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 P0560 until the test runs.

Does the scan tool indicate that DTC P0560 failed this ignition?

--

Go to Step 3

System OK