P1A56

DTC P1A56

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 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 wake-up signal.

Diagnostic Aids

Possible cable open or SGCM internal problem.

Reference Information
Schematic Reference

Hybrid Controls Schematics (Hybrid Controls Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Starter/Generator 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)

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