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 - ECM

### Diagnostic Fault Information

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

### Typical Scan Tool Data

#### Ignition 1 Signal - ECM

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Ignition ON, engine OFF. Parameter Normal Value: 12.6 Volts
IGN I | 0.0 Volts | 0.0 Volts | 12.6 Volts
Ground | 12.6 Volts | 0.0 Volts | --

### 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 if the voltage is out of range. If the ECM detects that the system voltage is too low, then DTC P0562 sets.

### Conditions for Running the DTC

The engine is running.

### Conditions for Setting the DTC

The ECM detects that the system voltage is less than 9 volts for 5 seconds.

### Action Taken When the DTC Sets

DTC P0562 is a type C DTC.

### Conditions for Clearing the DTC

DTC P0562 is a type C DTC.

### Diagnostic Aids

A low voltage DTC in multiple 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. Verify that an IPC DTC B1370 is not set.

⇒ | If the IPC DTC B1370 is set diagnose that DTC prior to this diagnostic.

2. Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 volts.

⇒ | If not within the specified range, refer to Charging System Test.

3. Observe the scan tool ECM Control Module Voltage Signal parameter. The reading should be between 12.6 and 15.0 volts.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at the ECM.
2. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the ground circuit terminal 73 X2 and ground.

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

3. Verify that a test lamp illuminates between the B+ circuit terminal 12 X1 and ground.

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

4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 14 X1 and ground.

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

5. 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.