P1A56
DTC P1A56
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC P1A56
- Hybrid System Voltage Discharge Circuit
Circuit/System Description
The starter/generator control module (SGCM) monitors connector X2 terminals 15 and 16. When the connector is disconnected, the SGCM capacitors are electrically connected to a discharge resistor.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
36-volt output voltage greater than 10 volts and discharge resistance error signal is ON for 1 second.
Action Taken When the DTC Sets
Hybrid system is disabled.
Conditions for Clearing the DTC
Clears 30 seconds after cycle wakeup signal.
Diagnostic Aids
Possible cable open or SGCM internal problem.
Reference Information
Schematic Reference
Hybrid Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Starter/Generator Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, inspect the SGCM X2 harness connector for poor connections, bent terminals or corrosion.
2. Reinstall SGCM X2.
3. Ignition ON, with a scan tool, clear the DTC.
4. Ignition OFF, wait 30 seconds.
5. Ignition ON, operate the vehicle within the Conditions for Running the DTC and verify the DTC does not reset.
If the DTC resets, replace the SGCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for SGCM replacement, setup, and programming