P0B9D – High Voltage in Hybrid/Electric Vehicle Battery Circuit 20

P0B9D Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix P0B9D Code

Check the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0B9D Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P0B9D Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack. 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up the first battery section. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The battery cross-section is section number three, it consists of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually repairable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

P0B9E – Intermittent/Erratic Hybrid Battery Voltage Detection Circuit

P0B9E Possible Causes

  • Faulty battery smart unit
  • Defective HV battery assembly

What Does It Mean?

How to Fix P0B9E Code

Check the “possible causes” listed above. Visually inspect the related cable harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

P0B9E Possible Symptoms

Check engine light on (or service engine soon warning light)

P0B9E Meaning

The HV battery uses nickel-metal hydride batteries and does not require external charging. The power management control ECU maintains the HV battery’s SOC (state of charge) at a constant level during driving. The HV battery consists of 28 modules, with each module containing eight 1.2V cells connected in series. The battery smart unit monitors the battery block voltage at 14 locations. Each battery block is composed of 2 modules in one assembly. The battery smart unit, which monitors battery block voltages, determines that a malfunction has occurred if the voltage difference between battery blocks exceeds the standard. When the malfunction detection condition is met, the power management control ECU (HV CPU) illuminates the malfunction indicator light (MIL) and sets a diagnostic trouble code (DTC).

P0B9F – Hybrid/Electric Vehicle Battery 21 Circuit

P0B9F Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix P0B9F Code

Check the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0B9F Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P0B9F Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack. 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up the first battery section. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The cross-section of the battery is section number three, it consists of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually repairable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A repairable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered repairable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

P0BA0 – Performance of Hybrid/Electric Vehicle Battery Circuit 21

P0BA0 Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix P0BA0 Code

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0BA0 Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P0BA0 Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up battery section one. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The battery cross section is section number three, it consists of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually serviceable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

P0BA1 – Low Voltage in Hybrid/Electric Vehicle Battery Circuit 21

P0BA1 Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix P0BA1 Code

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0BA1 Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P0BA1 Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack. 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up battery section one. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The battery cross-section is section number three, it consists of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually serviceable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

P0BA2 – High Voltage Hybrid/Electric Vehicle Battery 21 Electrical Circuit

P0BA2 Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix P0BA2 Code

Check the “Possible Causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0BA2 Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P0BA2 Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack. 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up the first battery section. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The battery cross-section is section number three, it consists of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually repairable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

P0BA3 – Intermittent/Erratic Hybrid Battery Voltage Detection Circuit “U

Code P0BA3: Definition, Causes, Symptoms, and Solutions


Meaning of Code P0BA3

Code P0BA3 indicates a problem related to the high voltage (HV) battery system of a hybrid or electric vehicle. More specifically, it signals an abnormal voltage difference between battery blocks, detected by the battery intelligent management unit.

  • The HV battery uses nickel-metal hydride cells and does not require external charging.
  • The Power Management ECU (Engine Control Unit) controls the battery’s state of charge (SOC).
  • The HV battery is composed of 28 modules, each module containing 8 cells of 1.2 V in series.
  • The intelligent unit monitors the voltage at 14 locations (each block = 2 modules). If the voltage difference between blocks exceeds a predefined threshold, code P0BA3 is triggered, illuminating the Malfunction Indicator Lamp (MIL).

Possible Symptoms

  • 🔴 Check Engine Light illuminated (or “Service Engine Soon”).
  • ⚠️ Hybrid/electric system warning on the dashboard.
  • ⚡ Potential decrease in vehicle performance (in limp mode).

Probable Causes

  1. Faulty Battery Intelligent Unit: Failure of the module monitoring the block voltages.
  2. Damaged HV Battery Assembly: Internal problem (e.g., unbalanced modules, faulty cells).
  3. Connection Issues:
  • Damaged or corroded cable harnesses.
  • Faulty connectors (broken, bent, or oxidized pins).

How to Diagnose and Repair Code P0BA3?

Preliminary Steps

  1. Reading Error Codes: Use an OBD2 scanner to confirm P0BA3 and check for any associated codes.
  2. Visual Inspection:
  • Check the HV battery cable harnesses and connectors.
  • Look for signs of corrosion, physical damage, or loose pins.

Corrective Actions

  • Repair Faulty Connectors: Clean corroded terminals, replace damaged pins.
  • Replace the Battery Intelligent Unit: If the monitoring module is faulty.
  • Check Battery Block Balancing: Use a specialized diagnostic tool to measure the voltage of each block.
  • HV Battery Intervention: If an imbalance persists, replace the faulty modules or the entire battery (requires a certified professional).

Important Precautions

  • 🔋 Electrical Safety: The HV battery operates at very high voltage. Always disconnect the power before any intervention.
  • 🔧 Expertise Required: This code involves critical components. Entrust complex repairs to a qualified technician.

In summary: Code P0BA3 points to a voltage imbalance in the high-voltage battery. A thorough inspection of the connectors and electrical components is essential. If basic repairs are not sufficient, an in-depth analysis of the HV battery and its management system will be necessary.

P0BA4 – Hybrid/Electric Vehicle Battery 22 Circuit

P0BA4 Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix P0BA4 Code

Check the “possible causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0BA4 Possible Symptoms

Check engine light on (or service engine soon warning light)

P0BA4 Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack. 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up the first battery section. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The battery cross-section is section number three, it consists of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually repairable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

P0BA5 – Performance of Hybrid/Electric Vehicle Battery Circuit 22

P0BA5 Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix Code P0BA5

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0BA5 Possible Symptoms

Check engine light on (or service engine soon warning light)

P0BA5 Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack. 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up the first battery section. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The battery cross-section is section number three, it is made up of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually repairable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, the battery energy control module wiring harness, the auxiliary battery wiring harness, and the battery energy control module are all considered serviceable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

P0BA6 – Low Voltage Hybrid/Electric Vehicle Battery 22 Circuit Voltage

P0BA6 Possible Causes

  • Defective hybrid/electric vehicle battery
  • Faulty hybrid/electric vehicle battery interface control module

What Does It Mean?

How to Fix P0BA6 Code

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0BA6 Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P0BA6 Meaning

The hybrid/electric vehicle battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV 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 DC. The battery cells are also grouped into three sections. The first 90 cells/30 cell groups make up the first battery section. This section is adjacent to the hood and contains batteries 67 to 96. Battery section two is located behind section one. It consists of 72 cells/24 cell groups and contains batteries 43 to 66. The battery cross section is section number three, it consists of the remaining 126 cells/42 cell groups and contains batteries 1 to 42. The three battery sections are individually repairable components.

The battery energy control module monitors the voltage of the 96 battery cell groups via the four hybrid/EV battery interface control modules. Voltage sensing circuits are attached to each individual cell group, and these sensing circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connects this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module via the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.

The battery energy control module will determine when a fault condition is present. System diagnostics and status are communicated from the battery energy control module to the hybrid/EV powertrain control module 2 via serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.