Hybrid Controls

DTC P0AA1

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 P0AA1
- Hybrid Battery Positive Contactor Circuit Stuck Closed

Circuit/System Description

The battery energy control module (BECM) monitors to detect a fault with the contactor.

The Link Voltage is the voltage on the 36 volt cable between the SGCM and the BECM, Pack voltage is the sum of all module voltages. refer to Hybrid Energy Storage Schematics (Electrical Diagrams) for detailed information.

Conditions for Running the DTC

Ignition to OFF, transition from contactor closed to contactor open.

Conditions for Setting the DTC

Absolute Value (Pack Voltage - Link Voltage) is less than 1 volt.

Action Taken When the DTC Sets

The hybrid system is disabled.

Conditions for Clearing the DTC

* State = Run or Service or Powerdown.
* Pack current is less than -0.1 amps.
* Contactor state = Open.
* Contactor status = Open Service Disconnect.
* Current sensor DTCs = Passed.
* Pack voltage reading = Valid.
* Pack voltage DTCs = Passed.

Reference Information
Schematic Reference

Hybrid Energy Storage Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Generator Battery Carrier 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 Verification

1. If there are any current DTCs set, diagnose those first, including any clearing any codes.
2. Cycle the ignition switch from OFF to RUN several times, allowing at least 5 seconds after each transition from Ignition OFF to RUN.

• If the DTC resets, replace the BECM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for BECM replacement, setup, and programming.