Engine Electrical
DTC P0562
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0562
- System Voltage Low
Diagnostic Fault Information
Circuit/System Description
The following control modules monitor the system voltage to ensure that the voltage stays within the proper range:
* Engine control module
* Fuel pump control module
Damage to components, and incorrect data may occur when the voltage is out of range.
Conditions for Running the DTC
Engine Control Module
* The system voltage is between 9.5-18 V.
* The engine is running.
Fuel Pump Control Module
The engine is running.
Conditions for Setting the DTC
Engine Control Module
The engine control module detects a system voltage below 10 V for 5 seconds.
Fuel Pump Control Module
The fuel pump control module detects that battery voltage is less than 9 V.
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.
Reference Information
Schematic Reference
* Engine Controls Schematics ([1][2]Electrical Diagrams) for the 3.6L (LLT) engine
* Engine Controls Schematics ([1][2]Electrical Diagrams) for the 6.2L (L99) and (LS3) engine
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Charging System Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Engine running, accessories OFF, measure and record the battery voltage at the C1 battery terminals. The voltage should be between 12.6 and 15.0 V.
• If not within the specified range, refer to Charging System Test (Charging System Test).
2. Observe the scan tool of the appropriate control module battery voltage parameter. The reading should be between 12.6 and 15.0 V. Verify that the scan tool displays a value that is within 2 V of the battery terminal voltage.
Circuit/System Testing
Engine Control Module
1. Ignition OFF, disconnect the harness connectors at the K20 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 terminals listed below and ground:
* Terminal 1 X2 (LLT)
* Terminal 2 X2 (LLT)
* Terminal 4 X2 (LLT)
* Terminal 73 X1 (L99, LS3)
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a 15 A fused jumper wire between B+ and the KR75 powertrain relay switch control terminal 87. Ignition ON, verify that a test lamp illuminates between the IGN/B+ circuit terminals listed below and ground:
* Terminal 56 X2 (LLT)
* Terminal 54 X2 (LLT)
* Terminal 3 X2 (LLT)
* Terminal 5 X2 (LLT)
* Terminal 6 X2 (LLT)
* Terminal 41 X2 (LLT)
* Terminal 20 X1 (L99, LS3)
* Terminal 19 X1 (L99, LS3)
* Terminal 47 X1 (L99, LS3)
* Terminal 18 X1 (L99, LS3)
• If the test lamp does not illuminate, test the IGN/B+ circuit for a short to ground or an open/high resistance.
4. If all circuits test normal, replace the K20 ECM.
Fuel Pump Control Module
1. Ignition OFF, disconnect the harness connectors at the K27 fuel pump control module.
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 25 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 IGN/B+ circuit terminals listed below and ground:
* Terminal 21
* Terminal 1
* Terminal 8
• If the test lamp does not illuminate, test the IGN/B+ circuit for a short to ground or an open/high resistance.
4. If all circuits test normal, replace the K27 fuel pump control module.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for the appropriate control module replacement, setup, and programming