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 P1A56: Hybrid System Voltage Discharge CircuitCircuit/System Description
The starter/generator control module (SGCM) monitors connector C2 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
Connector End View Reference
Hybrid Controls Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.
- Inspect harness connector C2 connection to the SGCM.
- If there is nothing wrong with the harness connector, replace the SGCM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for SGCM replacement, setup, and programming.
