Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P1AB0: Battery Pack Over CurrentCircuit/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
Description and Operation
Generator Battery Carrier Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References 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 |
- Verify the DTC is set as current.
- Test the condition of the hybrid battery pack fuse, replace the fuse if open. To gain access refer to Hybrid Battery Service Disconnect/Connect .
- Test the 36-volt positive cable for an open or high resistance.
| ⇒ | If the DTC is history refer to Testing for Intermittent Conditions and Poor Connections or diagnostic aids. |
| ⇒ | 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. |
| ⇒ | If there is an open or high resistance, replace the 36-volt positive cable. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
