P1AB0

DTC P1AB0

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 P1AB0
- Battery Pack Over Current




Circuit/System Description

The engine control module (ECM) monitors the hybrid battery pack for a high current condition.


Conditions for Running the DTC

The engine is running.


Conditions for Setting the DTC

Battery pack current is greater than 140 amps or less than -330 amps.


Action Taken When the DTC Sets

Hybrid system is disabled.


Conditions for Clearing the DTC

* Battery pack current is inside the threshold.
* Battery pack current = Valid
* Current sensor out of range diagnostics and performance (DTC P0AC0, P0AAC1, P0AC2, P1A48 and P1A49) = Not Fail



Diagnostic Aids

This diagnostic could occur in conjunction with a open hybrid battery fuse.


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.


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. Verify the DTC is set as current.

• If the DTC is history refer to Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics) or diagnostic aids.

2. Test the condition of the hybrid battery pack fuse, replace the fuse if open. To gain access refer to Hybrid Battery Service Disconnect/Connect ().

• If the hybrid battery fuse is open, test the 36-volt positive cable from the starter/generator control module (SGCM) to hybrid battery pack for a short to ground.

3. Test the 36-volt positive cable for an open or high resistance.

• If there is an open or high resistance, replace the 36-volt positive cable.




Repair Instructions

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


36-Volt Battery Positive Cable Replacement (Engine to Passenger Compartment) ()36-Volt Battery Positive Cable Replacement (Passenger Compartment to Module) ()