P0B93 Possible Causes

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

What Does It Mean?

How to Fix P0B93 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.

P0B93 Possible Symptoms

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

P0B93 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.

P0B94 Possible Causes

• Faulty battery smart unit
• Faulty HV battery assembly

What Does It Mean?

How to Fix Code P0B94

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

P0B94 Possible Symptoms

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

P0B94 Meaning

The HV battery uses nickel-metal hydride batteries and does not require external charging. The power management control ECU maintains the HV battery 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 consists 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).

P0B95 Possible Causes

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

What Does It Mean?

How to Fix Code P0B95

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.

P0B95 Possible Symptoms

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

P0B95 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.

P0B96 Possible Causes

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

What Does It Mean?

How to Fix P0B96 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.

P0B96 Possible Symptoms

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

P0B96 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 cross-section 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.

P0B97 Possible Causes

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

What Does It Mean?

How to Fix P0B97 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.

P0B97 Possible Symptoms

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

P0B97 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.

P0B98 Possible Causes

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

What Does It Mean?

How to Fix P0B98 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.

P0B98 Possible Symptoms

Check Engine Light illuminated (or Service Engine Soon warning light)

P0B98 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.

Code P0B99: Causes, Symptoms, and Solutions

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Meaning of Code P0B99

Code P0B99 is an OBD-II code specific to hybrid vehicles (Toyota, Lexus, etc.). It indicates that the battery intelligent unit has detected an excessive voltage difference between the blocks of the high voltage (HV) battery.

• The HV battery is composed of 28 modules, each module containing 8 cells of 1.2 V (i.e., 9.6 V per module).
• The intelligent unit monitors the voltage across 14 battery blocks (each block = 2 modules).
• If the voltage difference between these blocks exceeds the predefined thresholds, the HV CPU (Power Management ECU) records the P0B99 code and illuminates the check engine light (MIL).

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Possible Symptoms

• Malfunction Indicator Lamp (MIL) illuminated.
• Reduced hybrid system performance.
• Decreased electric range.
• Warning messages on the dashboard (e.g., “Hybrid System Problem”).

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Possible Causes

1. Faulty Battery Intelligent Unit:

• Failure of the voltage monitoring circuits.

1. HV Battery Imbalance:

• Faulty modules or cells within the battery pack.
• Premature aging of certain cells.

1. Electrical Problems:

• Damaged wiring or corroded connectors between modules.
• Short circuit or interruption in the battery harness.

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Diagnostic Procedures

1. Visual Inspection:

• Check the HV battery cable harness and connectors for cut wires, damaged insulation, or corrosion.
• Inspect the condition of the connector pins (bent, broken, or oxidized).

1. Intelligent Unit Data Analysis:

• Use a hybrid-compatible OBD-II scanner to read the voltages of the 14 battery blocks.
• Identify blocks with abnormally low or high voltages.

1. Battery Module Testing:

• Measure the voltage of each module using a multimeter (expected value: ~9.6 V).
• Compare the differences between modules (tolerance generally ≤ 0.3 V).

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Recommended Solutions

1. Re-balance or Replace Faulty Modules:

• If a module is out of specification, replace it with a new or remanufactured module.
• For minor imbalances, a rebalancing procedure via the diagnostic tool can be attempted.

1. Replace the Battery Intelligent Unit:

• If the unit is not communicating correctly, install a manufacturer-compliant unit.

1. Clean or Repair Wiring:

• Repair damaged wires and clean connectors with contact spray.

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Important Precautions

• High voltage danger: The HV battery generates over 200 V. Consult a certified technician for any intervention.
• Safe discharge: Before handling the battery, ensure it is disconnected and discharged.

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Estimated Costs

• HV Battery Module: €200 to €600 (depending on the model).
• Battery Intelligent Unit: €500 to €1,500.
• Labor: 2 to 6 hours (€200 to €800).

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Conclusion

Code P0B99 indicates a critical problem that can affect the reliability and safety of the hybrid vehicle. Prompt intervention is essential to avoid a complete breakdown or accelerated battery degradation. Due to the electrical risks and system complexity, it is highly recommended to entrust the diagnosis and repair to a hybrid vehicle specialist equipped with appropriate tools.

P0B9A Possible Causes

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

What Does It Mean?

How to Fix P0B9A 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.

P0B9A Possible Symptoms

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

P0B9A 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 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, 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.

P0B9B Possible Causes

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

What Does It Mean?

How to Fix P0B9B 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.

P0B9B Possible Symptoms

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

P0B9B 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 fault code diagnostic information.

P0B9C Possible Causes

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

What Does It Mean?

How to Fix P0B9C 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.

P0B9C Possible Symptoms

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

P0B9C 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.