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 Descriptors
DTC P1A48: Hybrid Battery High Current Sensor Circuit Low VoltageDTC P1A49: Hybrid Battery High Current Sensor Circuit High Voltage
Circuit/System Description
The battery energy control module (BECM) monitors current sensor 2 for circuit faults.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P1A48
Current sensor 2 raw A/D is less than 0.5 volt.
P1A49
Current sensor 2 raw A/D is greater than 4.5 volts.
Action Taken When the DTC Sets
The hybrid system is inactive.
Conditions for Clearing the DTC
Current sensor 2 raw A/D voltage returns inside thresholds.
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
Warning: 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.
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.
Important: In order to avoid damaging BECM X1 and X2 connector terminals, the proper test probes should be used. The proper test probes are as follows:
| • | J-35616-65B for female terminals |
| • | J-35616-64B for male terminals |
- Disconnect harness connector X1 for the BECM. Refer to Hybrid Battery Service Disconnect/Connect
- Disconnect current sensor harness.
- Test for less than 1 ohm between the following circuits:
- If all circuits test normal, replace the current sensor/BECM.
| • | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for BECM replacement, setup, and programming
