P0AA1

DTC P0AA1

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 P0AA1
- Hybrid Battery Positive Contactor Circuit Stuck Closed

Circuit/System Description

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

The Link Voltage is the voltage on the 36 V cable between the starter generator control module (SGCM) and the battery energy control module (BECM). Pack voltage is the sum of all module voltages, refer to Hybrid Energy Storage Schematics ([1][2]Electrical Diagrams) for detailed information.

Conditions for Running the DTC

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

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

* DTC P0AA1 is a type B DTC.
* The hybrid system is disabled.

Conditions for Clearing the DTC

* DTC P0AA1 is a type B 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 ([1][2]Electrical Diagrams)
Connector End View Reference

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

Generator Battery Carrier 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

Verify that no other DTCs are set.

If any other DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).

Circuit/System Testing

Warning

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.

Warning

To help avoid personal injury, be careful when working in the vicinity of the battery energy control module. Internal components will still be live, 36V potential, even when the cover has been opened or removed.

1. Ignition OFF, disable the high voltage at the generator battery, refer to Hybrid Battery Service Disconnect/Connect (Procedures).
2. Test for 1.35-1.65k ohm between the main conductor terminal X1 and the generator battery ground terminal X3.

• If not within the specified range, replace the generator battery control wiring harness.

3. Depress and hold the disconnect switch plunger.
4. Test for 1.35-1.65k ohm between the main conductor terminal X1 and X2.

• If not within the specified range, replace the generator battery control wiring harness.

5. If all circuits test normal, replace the generator battery disconnect control module.

Repair Instructions

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

* Battery Energy Control Module Wiring Harness Replacement (Battery Energy Control Module Wiring Harness Replacement)
* Control Module References (Programming and Relearning) for generator battery disconnect control module replacement, setup, and programming