P0AC2

DTC P0AC1 or P0AC2

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 Descriptors
DTC P0AC1
- Hybrid Battery Current Sensor Circuit Low Voltage

DTC P0AC2
- Hybrid Battery Current Sensor Circuit High Voltage




Circuit/System Description

The battery energy control module (BECM) monitors the current sensor circuit for a low and high voltage condition.


Conditions for Running the DTC

The engine is running.


Conditions for Setting the DTC

P0AC1

Current sensor 1 raw A/D is less than 0.2 volt.

P0AC2

Current sensor 1 raw A/D is greater than 4.8 volts.


Action Taken When the DTC Sets

Hybrid system is disabled.


Conditions for Clearing the DTC

Current sensor voltage returns to normal operating range.


Reference Information
Schematic Reference

Hybrid Energy Storage Schematics ()
Connector End View Reference

Component Connector End Views (Connector Views)
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
Special Tools

J 35616 GM Approved Terminal Test Kit


Circuit/System Testing

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.


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


Important: Use the following list to identify the appropriate terminals to test:



* J-35616-65B for female terminals
* J-35616-64B for male terminals


1. Disconnect harness connector X1 for the BECM. Refer to Hybrid Battery Service Disconnect/Connect ().
2. Disconnect current sensor harness.
3. Test for less than 1 ohm between the following circuits.

* X1 terminal 20 to current sensor connector terminal A
* X1 terminal 9 to current sensor connector terminal B
* X1 terminal 19 to current sensor connector terminal C
* X1 terminal 10 to current sensor connector terminal D


• If greater than specified value, replace the current sensor harness assembly.

4. If all circuits test normal, replace the current sensor/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