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Engine Fault Code P0B0C

Auxiliary Transmission Fluid Pump Hydraulic Leakage

Care Engine Code Reader
The Engine Fault Code P0B0C refers to a problem with the auxiliary transmission fluid pump, specifically indicating a hydraulic leakage. This code is often related to hybrid or electric vehicles that use an auxiliary pump to help with the transmission, especially when the main engine is off.

Heres a breakdown of what this code means:

1. Auxiliary Transmission Fluid Pump: This pump helps circulate transmission fluid, especially in hybrid vehicles, to ensure that the transmission operates smoothly even when the engine isn`t running.

2. Hydraulic Leakage: This indicates that there is a leak in the hydraulic system of the pump. This can lead to inadequate lubrication and cooling of the transmission, which may cause shifting issues or even transmission failure over time.

Alternative Meanings by Manufacturer

While P0B0C generally refers to the same issue, some manufacturers may have different interpretations or specific conditions related to this code. Here are some potential variations:

1. P0B0C in Toyota/Lexus: This could be related to the hybrid transmission system, indicating a specific issue with the electric motor or pump used in their hybrid models.

2. P0B0C in BMW: Similar to other manufacturers, it may refer to an issue with the auxiliary pump, but could also indicate a fault in the vehicle`s energy management system.

3. P0B0C in Ford: In Ford vehicles, this code may relate to the hybrid system`s operation, focusing on the auxiliary pumps performance and efficiency.

4. P0B0C in other manufacturers: Other European brands might have similar meanings, but its always good to check the specific service manual for any unique definitions or troubleshooting steps.

What to Do if You Encounter This Code

1. Inspect for Leaks: Check the area around the auxiliary pump for any signs of fluid leakage.

2. Check Fluid Levels: Ensure that the transmission fluid is at the proper level. Low fluid can cause overheating and damage.

3. Scan Tool: Use an OBD-II scanner to confirm the code and check for any additional codes that might provide more context.

4. Consult a Professional: If youre not comfortable diagnosing or repairing the issue, its best to consult a qualified mechanic, especially for complex systems like hybrids.

Fixing this issue promptly is crucial to maintaining your vehicle`s performance and longevity, especially in European models where transmission systems can be intricate.
The engine fault code P0B0C indicates a problem with the auxiliary transmission fluid pump, specifically related to hydraulic leakage. Heres a breakdown of the possible causes, which can vary by manufacturer and model:

1. Worn Seals or Gaskets: Over time, seals and gaskets in the transmission system can wear out, leading to leaks. This is common in older vehicles.

2. Damaged Pump: The auxiliary transmission fluid pump itself may be damaged or defective, causing it to leak fluid.

3. Loose Connections: If the connections to the pump are loose or improperly fitted, this can result in fluid leaks.

4. Fluid Contamination: Contaminated transmission fluid can cause wear on components, leading to leaks. This can happen if the fluid hasnt been changed regularly.

5. Overheating: If the transmission overheats, it can cause the fluid to expand and potentially lead to leaks.

6. Physical Damage: Any physical damage to the transmission or pump, such as from an accident, can also lead to hydraulic leakage.

Manufacturer-Specific Considerations:

Porsche: Porsche models may have specific issues with their dual-clutch systems that can lead to pump failures. Regular maintenance is key to preventing these issues.

Mini: Mini vehicles, particularly those with automatic transmissions, may experience issues with the fluid pump due to their compact design. Ensure proper fluid levels and check for leaks regularly.

Mercedes: Mercedes models often have complex transmission systems. Electrical issues can also trigger this code, so it`s important to check the electrical components as well.

Audi: Audi vehicles may have specific software updates that address transmission issues. Always check for the latest updates before diagnosing hardware problems.

Jaguar: Jaguar models can have unique hydraulic systems. Issues may arise from the software controlling the pump, so a scan for additional codes may be helpful.

Land Rover: Land Rover vehicles may suffer from water intrusion in the transmission system, leading to contamination and leaks. Regular inspections can help catch these issues early.

Our take, while the general causes of P0B0C are similar across brands, specific models may have unique issues or requirements. Always refer to the vehicles service manual for the most accurate diagnosis and repair procedures.
Fixing the Engine Fault Code P0B0C, which indicates an auxiliary transmission fluid pump hydraulic leakage, can vary based on the manufacturer and vehicle model. Here are some general steps and manufacturer-specific tips:

General Steps to Fix P0B0C:

1. Check for Leaks:
– Inspect the area around the auxiliary transmission fluid pump for any visible fluid leaks. Look for wet spots or dripping fluid.

2. Inspect Connections:
– Check all hoses and connections leading to the pump. Ensure they are tight and not cracked or damaged.

3. Fluid Level Check:
– Check the transmission fluid level. If it`s low, top it off with the correct type of fluid.

4. Examine the Pump:
– If there`s a significant leak, the pump itself may need to be replaced. Remove the pump and inspect it for damage.

5. Replace Seals and Gaskets:
– If you find worn seals or gaskets, replace them to prevent future leaks.

6. Clear the Code:
– After repairs, use an OBD-II scanner to clear the fault code and test drive the vehicle to ensure the issue is resolved.

Manufacturer-Specific Tips:

#Porsche:
– Check for Software Updates: Sometimes, software issues can cause false codes. Ensure your vehicle`s software is up to date.

#Mini:
– Inspect the Transmission Control Module (TCM): A faulty TCM can cause issues with the fluid pump operation. If you suspect this, have it tested.

#Mercedes:
– Fluid Type Matters: Ensure you use the correct transmission fluid type, as specified in your owner`s manual. Using the wrong fluid can lead to pump issues.

#Audi:
– Look for Recalls: Some Audi models may have recalls related to transmission issues. Check with the dealer to see if your vehicle is affected.

#Jaguar:
– Check for Warranty: If your vehicle is still under warranty, consider taking it to a dealer for repairs, as they may cover the cost.

#Land Rover:
– Diagnostic Tools: Use a Land Rover-specific diagnostic tool, as they can provide more detailed insights into transmission issues.


Fixing the P0B0C code involves checking for leaks, inspecting the pump and connections, and ensuring the correct fluid level. Depending on the manufacturer, additional steps like software updates or specific diagnostic tools may be necessary. Always refer to the vehicle`s service manual for detailed instructions. If you`re unsure, consulting a professional mechanic is a good idea.
Driving with a P0B0C code, which indicates an auxiliary transmission fluid pump hydraulic leakage, is generally not safe. This code suggests that there is a problem with the hydraulic system that helps the transmission operate properly. Heres a breakdown of what you should consider for different manufacturers:

General Considerations:
1. Transmission Performance: A leak can lead to low fluid levels, which may cause the transmission to slip or not shift properly.
2. Overheating: Insufficient fluid can cause the transmission to overheat, leading to more severe damage.
3. Safety Risks: If the transmission fails while driving, it could lead to loss of control, posing a safety risk.

Manufacturer-Specific Notes:

1. Porsche:
– Porsche vehicles often have advanced transmission systems. A leak can lead to significant performance issues. It`s best to avoid driving until its fixed.

2. Mini:
– Mini vehicles, especially those with automatic transmissions, can be sensitive to fluid levels. Driving with this code can lead to erratic shifting and potential transmission failure.

3. Mercedes:
– Mercedes-Benz vehicles usually have sophisticated transmission management systems. A hydraulic leak could trigger limp mode, limiting performance and potentially causing safety issues.

4. Audi:
– Audi vehicles often have complex transmission systems. A hydraulic leak can lead to severe transmission damage if not addressed, so it`s advisable to refrain from driving.

5. Jaguar:
– Jaguar transmissions are designed for performance. A hydraulic leak can cause shifting issues and may lead to complete transmission failure, making it unsafe to drive.

6. Land Rover:
– Land Rover vehicles are built for rugged use, but a hydraulic leak can affect off-road capabilities and overall safety. Its best to get it checked before driving.


Our view, it`s best to avoid driving a vehicle with a P0B0C code until the issue is resolved. Transmission problems can escalate quickly, leading to costly repairs and safety risks. Always consult a professional mechanic for a thorough diagnosis and repair.

OBD Codes Explained

Engine Codes

P is for PowerTrain - Engine and Transmission.

P0 Indicates Generic Powertrain Codes

P0 Codes indicate problems with the powertrain and are common for all vehicles using the OBD-II Standard.

P1 Enhanced Manufacturer Specific Codes

P1 Codes are specific to manufacturers.

Sub-System

The 3rd Digit indicates the Sub-System

1 – Emission Management

2 – Injector Circuit

3 – Ignition

4 – Emission Control

5 – Vehicle Speed and Idle

6 – Computer and Output

7 – Transmission

8 – Transmission

9 – Reserved

0 – Reserved

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