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 P0A9D: Hybrid Battery 1 Temperature Sensor Circuit Low VoltageDTC P0A9E: Hybrid Battery 1 Temperature Sensor Circuit High Voltage
DTC P0AC7: Hybrid Battery 2 Temperature Sensor Circuit Low Voltage
DTC P0AC8: Hybrid Battery 2 Temperature Sensor Circuit High Voltage
DTC P0ACC: Hybrid Battery 3 Temperature Sensor Circuit Low Voltage
DTC P0ACD: Hybrid Battery 3 Temperature Sensor Circuit High Voltage
DTC P0AEA: Hybrid Battery 4 Temperature Sensor Circuit Low Voltage
DTC P0AEB: Hybrid Battery 4 Temperature Sensor Circuit High Voltage
DTC P1A1A: Hybrid Battery 5 Temperature Sensor Circuit Low Voltage
DTC P1A1B: Hybrid Battery 5 Temperature Sensor Circuit High Voltage
DTC P1A1D: Hybrid Battery 6 Temperature Sensor Circuit Low Voltage
DTC P1A1E: Hybrid Battery 6 Temperature Sensor Circuit High Voltage
Circuit/System Description
Each battery module has a separate temperature sensor, or thermistor. These sensors are serviced as a pair (2 sensors for each battery module). The battery module must be removed from the vehicle in order to access the thermistors. These sensors receive power and provide a battery temperature feedback signal to the battery energy control module (BECM), through the generator battery temperature sensor wiring harness.
The battery temperature sensor is a 2-wire 10k ohm thermistor. The BECM supplies 5 volts and a low reference circuit to determine battery temperature.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P0A9D, P0AC7, P0ACC, P0AEA, P1A1A, P1A1D
Temperature sensor less than 0.5 volt.
P0A9E, P0AC8, P0ACD, P0AEB, P1A1B, P1A1E
Temperature sensor greater than 4.5 volts.
Action Taken When the DTC Sets
If more than 2 circuit faults are detected the hybrid system is disabled.
Conditions for Clearing the DTC
The affected battery temperature sensor returns to a normal operating range.
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 Verification
P0A9D, P0AC7, P0ACC, P0AEA, P1A1A, P1A1D
With a scan tool observe the battery temperature sensor parameter for the affected sensor. The parameter should display greater than 0.5 volt to pass.
P0A9E, P0AC8, P0ACD, P0AEB, P1A1B, P1A1E
With a scan tool observe the battery temperature sensor parameter for the affected sensor. The parameter should display less than 4.5 volts.
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:
P0A9D-P0A9E
Battery 1A temperature sensor terminals 3 and 4
P0AC7-P0AC8
Battery 1B temperature sensor terminals 5 and 6
P0ACC-P0ACD
Battery 2A temperature sensor terminals 7 and 8
P0AEA-P0AEB
Battery 2B temperature sensor terminals 13 and 14
P0A1A-P0A1B
Battery 3A temperature sensor terminals 15 and 16
P0A1D-P0A1E
Battery 3B temperature sensor terminals 17 and 18
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 |
Important: The following test must be performed when the battery pack has equalized at room temperature. An increase or decrease in temperature will cause resistance to change and may result in invalid test results.
- Ignition OFF, disconnect harness connector X1 from the BECM. Refer to Hybrid Battery Service Disconnect/Connect .
- Test for 10.5-11.5k ohms between the applicable temperature sensor circuit terminals.
- If all circuits test normal, replace the BECM.
| ⇒ | If not within the specified range, test or replace the applicable temperature sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BECM replacement, setup, and programming |
