GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1995 🢒 Sunfire 🢒 DTC 🢒 DTC P0562 System Voltage Low

Circuit Description

The powertrain control module (PCM) monitors the system voltage on the ignition feed terminals to the PCM. A system voltage DTC will set whenever the voltage is below a calibrated value.

Conditions for Setting
    • The system voltage is less than 10 volts.
    • The fault is present for 240 seconds.

Action Taken

The PCM will disable all outputs.

Conditions for Clearing the MIL/DTC
    • A history DTC will clear after 40 consecutive ignition cycles have occurred without a fault.
    • History and current DTC P0562 can be cleared by using a scan tool.

Diagnostic Aids

Charging the battery with a battery charger and starting the engine may set a DTC. If the DTC sets when an accessory is operated, check for a poor connection or excessive current draw.

Test Description

  1. This checks if the generator is faulty under load conditions. If the voltage is greater than 17 volts, go to Sections 6D3 and 8A.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Was the On-Board Diagnostic (OBD) System Check performed?

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Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Install a scan tool.
  2. Select IGNITION VOLTS on the scan tool.
  3. Start the engine and raise the engine speed to specified value.
  4. Load the electrical system by turning on the headlights, high blower, etc.

is the ignition volts greater than the specified value?

2,000 RPM

10 V

Go to Diagnostic Aids

Go to Step 3

3

Using a DVM, measure the battery voltage at the battery.

Is the battery voltage greater than the specified value?

10 V

Go to Step 4

Go to Starting/Charging

4
  1. Ignition OFF.
  2. Disconnect the PCM connector at the PCM.
  3. Ignition ON, engine OFF.
  4. Using a DVM, measure the ignition voltage at the PCM ignition feed circuits.

Is the ignition voltage greater than the specified value?

10 V

Go to Step 5

Go to Step 6

5
  1. Inspect for faulty connection at the PCM harness.
  2. repair as necessary.

Was a repair necessary?

--

Go to Powertrain On Board Diagnostic (OBD) System Check

Go to Step 7

6

Repair the open ignition feed circuit to the PCM.

Is the action complete?

--

Go to Powertrain On Board Diagnostic (OBD) System Check

--

7

Replace the PCM.

Is the action complete?

--

Go to Powertrain On Board Diagnostic (OBD) System Check

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