P0A29 Fault Code

Hybrid Battery Power Off Circuit High

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0A29 fault code indicates an issue with the hybrid battery power off circuit being too high. This problem can occur in hybrid vehicles when the engine control unit detects an abnormal high voltage condition in the circuit that regulates the power from the hybrid battery. This could potentially indicate a malfunctioning battery management system or an issue with the wiring and connectors in the circuit.

What are the symptoms of the P0A29 code?

When a P0A29 code is present, the following symptoms may be observed:

• Warning lights on the dashboard, particularly the check engine light or hybrid system light.
• Reduced performance or power from the hybrid system.
• In some cases, the vehicle may enter a limp mode, restricting performance further.
• An increase in fuel consumption due to the hybrid system not operating effectively.

What causes the P0A29 code?

Several factors can lead to the P0A29 fault code, including:

• Faulty or damaged wiring in the hybrid battery power circuit.
• A failed battery management system (BMS) that is not correctly regulating the battery voltage.
• Issues with the hybrid battery itself, such as cell imbalances or degradation.
• Corrosion at battery terminals or connectors leading to poor electrical connections.

How to fix P0A29?

To resolve a P0A29 fault code, follow these steps:

• Inspect the wiring and connectors related to the hybrid battery power circuit for any signs of damage, corrosion, or loose connections.
• Test the battery management system to ensure it is functioning properly.
• Balance the hybrid battery cells if they are found to be imbalanced.
• Replace any faulty components, including the BMS or damaged wiring, as necessary.
• After repairs, clear the fault codes and perform a road test to confirm the issue is resolved.