P1FEF Buick Code - Hybrid/EV Battery Interface Control Module 7 Voltage Sensor Performance

The hybrid battery contains 192 individual cells. Two cells are welded together in parallel and called a cell group. There are a total of 96 cell groups in the hybrid battery assembly. These cell groups are electrically connected in series. Each individual cell group is rated at 3.7 V, for a nominal system voltage of 355 V direct current. The battery cell groups are joined to form 3 distinct sections. The first 24 battery cell groups make up battery section 1. This section is adjacent to the cowl and contains battery cell groups 73 through 96. The next 28 battery cell groups make up battery section 2. This section is located behind section 1 and contains battery cell groups 45 through 72. The transverse battery section is section number 3 and it contains the remaining 44 battery cell groups 1 through 44. The battery sections also contain two temperature sensors, with one sensor located at each end of the section.
The battery energy control module monitors the voltage of the 96 battery cell groups. The voltage sense lines are attached to each individual cell group, and these sense lines terminate at a connector located on the top surface of the battery section. A voltage sense harness joins this connector to the battery energy control module.
The battery energy control module contains internal interface control modules that monitor specific cell groups.
The battery energy control module will determine when a fault condition is present. Diagnostics and system status are communicated from the battery energy control module to the hybrid powertrain control module 2 through serial data. The hybrid powertrain control module 2 is the host controller for diagnostic trouble code information.

• Faulty Hybrid/EV Battery Interface Control Module
• Hybrid/EV Battery Interface Control Module harness is open or shorted
• Hybrid/EV Battery Interface Control Module circuit poor electrical connection