GM Service Manual Online
For 1990-2009 cars only

Object Number: 369145  Size: MF
Engine Controls Components
Engine Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM monitors system voltage on the PCM ignition feed circuit. If the system voltage is out of tolerance, DTC P0560 will be set. When the conditions that set DTC P0560 are present, operation of some vehicle systems and components may be affected.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

    • System voltage monitored at the PCM ignition feed circuit is less than 10 volts or more than 16 volts.
    • Above conditions must be present for more than 25 seconds.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Inspect for the following:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

    • Loose terminal connection
       -  Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
       -  Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
    • Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
    •  Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

DTC P0560 - System Voltage

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Is DTC P1635 also set?

--

Go to DTC P1635 5 Volt Reference 1 Circuit

Go to Step 3

3

  1. Start and run engine above 1000 RPM.
  2. With a scan tool, observe the ignition 1 voltage parameter.

Does the scan tool indicate voltage within the specified range?

10-16V

Go to Step 4

Go to Step 5

4

  1. Turn ON the ignition, with the engine OFF.
  2. Operate the vehicle within Fail Records conditions.

Does the scan tool indicate this DTC failed this ignition?

--

Go to Step 5

Go to Diagnostic Aids

5

  1. Connect a J 39200 DMM between the battery terminals.
  2. Observe the voltage while running the engine above 1000 RPM.

Does the voltage measure within the specified range?

10-16V

Go to Step 6

Go to Step 7

6

  1. Load the electrical system by turning ON the headlamps and the HVAC high blower.
  2. Observe the DMM voltage while running the engine above 2000 RPM.

Does the voltage measure within the specified range?

10-16V

Go to Step 8

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Disconnect the generator.
  3. Measure the voltage on the generator control circuit using a DMM that is connected to a good ground.
  4. Start the engine.
  5. With a scan tool, command the Gen. L Term. ON.

Does the voltage measure near the specified value with the Gen. L Term. commanded ON?

5V

Go to Step 12

Go to Step 10

8

Compare the ignition 1 voltage parameter on the scan tool with the actual battery voltage read with the DMM.

Do the voltages match?

--

Go to Diagnostic Aids

Go to Step 9

9

Inspect the PCM ignition feed circuit for a poor connection between the ignition switch and the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

10

Test the generator control circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 11

11

Inspect the generator control circuit for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 13

12

Inspect the generator control circuit for a poor connection at the generator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Charging System Test in Engine Electrical

13

Important:: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Did you complete the replacement?

--

Go to Step 14

--

14

  1. Start and run the engine above 1000 RPM.
  2. With a scan tool, observe ignition 1 voltage parameter.

Does the scan tool indicate voltage within the specified range?

10-16V

System OK

Go to Step 5