For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC P0562: System Voltage Low

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
IGN I | P0562 | P0562 | -- | --
Ground | -- | P0562 | -- | --

### Circuit/System Description

The engine control module (ECM) monitors the system voltage to ensure that the voltage stays within the proper range. Damage to components, and incorrect data may occur when the voltage is out of range.

### Conditions for Running the DTC

• | The vehicle speed is above 8 km/h (5 mph).

• | The system voltage is between 9.5-18 volts.

### Conditions for Setting the DTC

The ECM detects a system voltage below 10 volts for 5 seconds.

### Action Taken When the DTC Sets

DTC P0562 is a C type DTC.

### Conditions for Clearing the DTC

DTC P0562 is a C type DTC.

### Diagnostic Aids

• | A low voltage DTC set in multiple control modules indicates a concern in the charging system.

• | A low voltage value in multiple control modules indicates a concern in the charging system.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Charging System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine running measure and record the voltage at the battery terminals. Verify that the battery voltage is 12.6-15.5 volts.

⇒ | If the battery voltage is not within the specified range, refer to Charging System Test

2. Engine running, observe the scan tool battery voltage parameter.
3. Verify the battery and scan tool battery voltage parameter readings do not differ more than 2.0 volts.

### Circuit/System Testing

1. Verify that DTC P0562 is set as current.
2. Ignition OFF, disconnect the harness connectors at the ECM.
3. Ignition OFF, test for less than 3.0 ohms between the ground circuit terminal 1 X3 to ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

4. Ignition ON, verify a test lamp illuminates between the Ignition 1 signal circuits terminal 31 X2 and terminal 47 X2 to ground.

⇒ | If the test lamp did not illuminate , test the affected Ignition 1 circuit for a short to ground or an open/high resistance.

5. Ignition ON, verify a test lamp illuminates between the battery positive voltage circuit terminal 32 X2 and ground.

⇒ | If the test lamp did not illuminate , test the B+ circuit for a short to ground or an open/high resistance.

6. If all circuits test normal, replace the ECM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming.