GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Sunfire 🢒 Engine 🢒 Engine Electrical 🢒 DTC P0562 System Voltage Low

Object Number: 563950 Size: SF
Engine Controls Components
Power, Ground, MIL, and DLC
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice

Circuit Description

The powertrain control module (PCM) monitors the ignition voltage on the ignition positive voltage circuit to the PCM. A system voltage DTC will set whenever the voltage is more than or less than a calibrated value.

Conditions for Running the DTC
  1. The engine speed is more than 1300 RPM.
  2. VSS is more than 8.045 km/n (5 MPH)

Conditions for Setting the DTC

The ignition voltage is less than 10 volts for 240 seconds.

Action Taken When the DTC Sets
    • The PCM will record the operating conditions at the time during which the diagnostic fails. This information will store in the Failure Records buffer.
    • A history DTC stores.
    • The coolant fan turns ON.

Conditions for Clearing the MIL/DTC
    • A history DTC will clear after 40 consecutive warm-up cycles without a fault.
    • Use a scan tool to clear the DTCs.

Diagnostic Aids
    • If the DTC sets when you operate an accessory, inspect for a faulty electrical connection or an excessive current draw.
    • Thoroughly inspect any suspected circuitry for the following conditions:
       - Backed-out terminals
       - Improper mating
       - Broken locks
       - Improperly formed connectors
       - Damaged terminals
       - Faulty terminal to wiring connections
       - Physical damage to the wiring harness

Test Description

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

  1. The Powertrain On-Board Diagnostic (OBD) System Check prompts you to complete some of the basic checks and to store the Freeze Frame and Failure Records data on the scan tool if applicable. This creates an electronic copy of the data that was captured when this DTC set. The scan tool stores this data for later reference.

    2.

  2. This step checks if the generator is malfunctioning during load conditions.

    3.

  3. This step checks the ignition positive voltage circuit for any excessive resistance. An open circuit will cause a no start condition.

    4.

  4. Reprogram the replacement PCM. Refer to the latest Techline™ procedures for PCM reprogramming.

    5.

  5. If no malfunctions are present at this point and no additional DTCs were set, refer to Diagnostic Aids for additional checks and information.

DTC P0562-System Voltage Low

Step

Action

Value(s)

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

  1. Install a scan tool.
  2. Start the engine.
  3. Raise the engine speed to the specified value.
  4. Load the electrical system by turning on the following items:
    5. • The headlights
    • The high blower motor
    • The ear defroster

Is the ignition 1 voltage on the scan tool less than the specified value?

1,400 RPM

10 V

Go to Step 3

Go to Step 8

3
  1. Run the engine at the specified value.
  2. Measure the battery voltage at the battery using a DMM.

Is the battery voltage more than the specified value?

1,400 RPM

12 V

Go to Step 4

Go to Charging System Test in Engine Electrical.

4

  1. Turn OFF the ignition.
  2. Disconnect the PCM electrical connectors.
  3. Check the ignition positive voltage circuit for high resistance.

Is the resistance on the ignition positive voltage circuit more than the specified value?

4 ohms

Go to Step 6

Go to Step 5

5
  1. Turn OFF the ignition.
  2. Check for a faulty connection at the PCM.
  3. Repair the connection as necessary. Refer to Wiring Repairs in wiring systems.

Was a repair necessary?

--

Go to Step 8

Go to Step 7

6
  1. Turn OFF the ignition.
  2. Repair the high resistance in the ignition positive voltage circuit. Refer to Wiring Repairs in wiring systems.

Is the action complete?

--

Go to Step 8

--

7

Important: Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 8

--

8
  1. Using the scan tool, clear the DTCs.
  2. Start the engine.
  3. Idle the engine at the normal operating temperature.
  4. Operate the vehicle within the Conditions for Running this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic ran and passed?

--

Go to Step 9

Go to Step 2

9

Check to see if any DTCs are set.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to applicable DTC table

System OK