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 12VDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
12V B+ | P0562 | P0562 | P0563 | -- |
Ground | -- | P0562 | P0563 | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Ignition ON, engine OFF. Parameter Normal Value: 12.6 V | |||
Ignition | 0.0 V | 0.0 V | 12.6 V |
Circuit/System Description
The engine control module (ECM) monitors the 12V battery positive (B+) 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. If the ECM detects low 12V battery voltage, then DTC P0562 will set.
Conditions for Running the DTC
| • | The vehicle speed is greater than 8 km/h (5 mph). |
| • | The 12V system voltage is between 9.5-18 V. |
Conditions for Setting the DTC
The ECM detects a system voltage less than 10 V.
Action Taken When the DTC Sets
| • | The ECM will command the charge indicator to be illuminated on the instrument panel cluster (IPC). |
| • | The ECM will not illuminate the malfunction indicator lamp (MIL). |
| • | The ECM will store conditions, which were present when the DTC set as Fail Records data only. |
Conditions for Clearing the DTC
| • | The ECM will command the message OFF after one trip in which the diagnostic test has been run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
Diagnostic Aids
| • | A low voltage DTC in multiple modules indicates a concern in the charging system. |
| • | Inspect the ground connection G103. Verify that the connection is clean and tight. |
Reference Information
Schematic Reference
| • | Control Module References for ECM schematics |
Connector End View Reference
Description and Operation
Charging System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, accessories OFF, measure and record the battery voltage at the 12V battery terminals. The voltage should be between 12.6 and 15.0 V.
- Observe the scan tool ECM Ignition 1 Signal parameter. The reading should be between 12.6 and 15.0 V.
| ⇒ | If not within the specified range, refer to Charging System Test. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connectors at the ECM.
- Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the following ground circuit terminals and ground:
- Verify that a test lamp illuminates between the 12V B+ circuit terminal 20 X1 and ground.
- If all circuits test normal, replace the ECM.
| • | Terminal 73 X1 |
| • | Terminal 73 X2 |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the 12V B+ circuit for a short to ground or an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming.
