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For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Shelby Series 1 🢒 Engine 🢒 Engine Controls - 4.0L 🢒 DTC P0562 System Voltage Low

Circuit Description

The powertrain control module (PCM) continuously monitors the system voltage. The system voltage information is taken from the PCM ignition feed circuits. Voltages below 8.0 volts or above 18.0 volts causes improper system operation and/or component damage. The PCM operates in a default mode if a PCM voltage diagnostic trouble code (DTC) sets. The PCM disables most outputs to protect the hardware if the system voltage is high. A scan tool may not display data if system voltage is below 8.0 volts. Use a DMM to monitor the system voltage in order to verify if the fault is currently present. A low voltage may cause a stalling condition, or other driveability concerns.

Conditions for Running the DTC
    • The engine run time is longer than 10 seconds.
    • The engine speed is more than 1,000 RPM.
    • The vehicle speed is more than 8 km/h (5 mph).

Conditions for Setting the DTC
    • The PCM senses system voltage below 8.0 volts.
    • All the above conditions are present for 2 seconds.

Action Taken When the DTC Sets
    • The PCM stores DTC P0562 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.
    • The PCM will command a high idle speed.
    • The transmission defaults to third gear.
    • The torque converter clutch (TCC) operation is inhibited.

Conditions for Clearing the DTC
    • A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
    • A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Use a scan tool in order to clear the DTC.

Diagnostic Aids

Important: 

   • Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
   • For any test that requires probing the PCM or a component harness connector, use the J 35616 connector test adapter kit. Using this kit prevents damage to the harness and component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

    • The following may cause an intermittent:
       - Poor connections -- Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
       - Corrosion
       - Mis-routed harness
       - Rubbed through wire insulation
       - Broken wire inside the insulation
    • An extremely low voltage, below 7.5 volts, may cause the loss of serial data and the MIL may not function. An open ignition feed circuit causes a no start and the MIL will not illuminate. A low system voltage may cause other DTCs to set.
    •  For an intermittent condition, refer to Symptoms .

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step tests the charging system under load at idle. The voltage should remain above 8 volts.

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

  1. Turn the ignition ON.
  2. Monitor the ignition 1 voltage using the scan tool.

Does the scan tool display the specified value?

B+

Go to Charging System Check in Engine Electrical

Go to Step 3

3

Inspect the PCM IGN fuse

Is the fuse open?

--

Go to Step 6

Go to Step 4

4
  1. Turn OFF the ignition.
  2. Disconnect the PCM connector C1 located on the same side as the manufacturer logo. Refer to Powertrain Control Module Replacement/Programming .
  3. Turn ON the ignition leaving the engine OFF.
  4. Measure the voltage at the PCM harness connector terminal for the ignition feed circuit using the DMM. Refer to Measuring Voltage in Wiring Systems.

Is the voltage at the specified value?

B+

Go to Step 7

Go to Step 5

5

Test the continuity of the ignition feed circuit using the DMM. Refer to Testing for Continuity in Wiring Systems.

Does the DMM display continuity below the specified value?

5 ohms

Go to Step 7

Go to Step 6

6
  1. Repair the ignition feed circuit to the PCM for an open or a short to ground. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the PCM IGN fuse if necessary.

Is the action complete?

--

Go to Step 9

--

7
  1. Inspect for poor connections at the PCM. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
  2. If you find a poor connection repair the condition as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

8

Important:: The replacement PCM must be programmed.

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

Is the action complete?

--

Go to Step 9

--

9
  1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
  2. Idle the engine at the normal operating temperature.
  3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

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

--

Go to Step 10

Go to Step 2

10

Select the Capture Info option and the Review Info option using the scan tool.

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

--

Go to the applicable DTC table

System OK