For 1990-2009 cars
Engine Controls Components
Cell 23: Power, Ground, MIL, and DLC
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The Powertrain Control Module (PCM) monitors the ignition voltage on the ignition positive voltage #2 circuit to the PCM. A system voltage DTC will set whenever the voltage is above or below a calibrated value.

### Conditions for Setting the DTC

• | The engine speed is greater than 1300 RPM.

• | 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.

• | A scan tool can clear the MIL/DTCs.

### Diagnostic Aids

• | If the DTC sets when you operate an accessory, check for a poor electrical connection or an excessive current draw.

• | Thoroughly check any suspected circuitry for the following conditions:

- | Backed out terminals

- | Improper mating

- | Broken locks

- | Improperly formed connectors

- | Damaged terminals

- | Poor terminal to wiring connections

- | Physical damage to the wiring harness

### Test Description

The number(s) below refer(s) to the step number(s) on the Diagnostic Table.

1. The Powertrain 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 captured when this DTC set. The scan tool stores this data for later reference.

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

3. The PCM Controlled Generator Diagnosis will further check the PCMs control of the generator.

4. This step checks the ignition positive voltage circuit #2 for any excessive resistance. An open circuit will cause a no start condition.

5. Reprogram the replacement PCM and perform the crankshaft position system variation learn procedure. Refer to the latest Techline procedures for PCM reprogramming and the Crankshaft Position System Variation Learn for the crankshaft position system variation learn procedure.

6. 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:

• | Headlights

• | Turning on the high blower motor,

• | Rear 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 greater than the specified value?

1,400 RPM

12 V

Go to Step 4

Go to Powertrain Control Module Controlled Generator Diagnosis

4 |

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

Is the resistance on the ignition voltage circuit greater than the specified value?

0 ohms

Go to Step 6

Go to Step 5

5 |

1. Turn OFF the ignition switch.
2. Check for a malfunctioning terminal connection at the PCM.
3. Repair the electrical connection as necessary. Refer to Connector Repairs in Wiring Systems.

Was a repair necessary?

--

Go to Step 8

Go to Step 7

6 |

1. Turn OFF the ignition switch.
2. Repair the poor electrical connection (high resistance) in the ignition positive voltage circuit #2. Refer to Connector Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 8

--

7 |

1. Turn OFF the ignition switch.
2. Replace the PCM. Refer to the Powertrain Control Module Replacement .

Is the action complete?

--

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 setting this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic has 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