P0B79 - Hybrid Battery Pack Voltage Malfunction in Toyota and Honda Models

Quick Answer

P0B79 means: DTC P0B79 indicates a malfunction in the hybrid battery pack voltage.

Fix: Check and replace faulty components Cost: $1,500 - $3,500 Time: 90-180 minutes

Can I drive with P0B79? Immediate action is recommended to avoid further damage.

Common Questions

What does P0B79 mean and how does it affect my car?

DTC P0B79 indicates a malfunction in the hybrid battery voltage, leading to potential performance issues. If left unresolved, it could cause your hybrid vehicle to run inefficiently or not start at all, impacting both safety and reliability.

What are the most common causes of P0B79 and how much does it cost to fix?

The most common cause is faulty battery cells, which can be expensive to replace, costing between $1,500 - $3,500. Other causes include poor connections and faulty control modules, with repair costs varying depending on the severity of the issue.

Can I drive my car with P0B79 or should I stop immediately?

It’s advisable to stop driving your vehicle immediately if you see the P0B79 code. Continuing to drive can lead to more severe battery damage, increased repair costs, and safety hazards.

How can I diagnose P0B79 myself using GeekOBD APP?

You can use the GeekOBD APP to scan your vehicle for DTCs. It will provide you with specific codes and freeze-frame data that can help you understand the conditions in which the P0B79 code was triggered, aiding in your diagnosis.

What vehicles are most commonly affected by P0B79?

Commonly affected vehicles include the 2010-2015 Toyota Prius and 2010-2015 Honda Insight. These models have been reported to experience this specific issue, so it's worthwhile to keep an eye on the health of your hybrid battery.

How can I prevent P0B79 from happening again?

Regular maintenance, including checking battery connections and monitoring battery health, can help prevent the P0B79 code from appearing again. Additionally, using the GeekOBD APP periodically for diagnostics can help catch issues early.

What is P0B79?

The DTC P0B79 code indicates a malfunction in the hybrid battery pack voltage, often found in hybrid vehicles such as the Toyota Prius (2010-2015) and Honda Insight (2010-2015). This code is triggered when the hybrid control module detects that the voltage level of the battery pack is outside the acceptable range. In simpler terms, it means there’s a problem with the battery that powers the electric motor in your hybrid car. If not addressed, this issue can lead to decreased fuel efficiency, reduced power during acceleration, and potential failure to start the vehicle. The malfunction can stem from several factors including faulty battery cells, poor connections, or issues with the hybrid control module itself. Ignoring this code can potentially lead to more severe damage and costly repairs down the line, making it crucial for drivers to seek immediate diagnostics and repairs. Note that this problem may also come accompanied by other signs such as reduced engine performance and increased emissions. Therefore, understanding the implications of the P0B79 code is essential for maintaining the reliability and efficiency of hybrid vehicles.

System: P - Powertrain (Engine, Transmission, Emissions)

Symptoms

Common symptoms when P0B79 is present:

  • Check engine light is illuminated, indicating a need for diagnostics.
  • Reduced power and responsiveness during acceleration, which can lead to a sluggish driving experience.
  • Fuel economy may drop significantly, often by 10-15%, affecting your overall driving costs.
  • The vehicle may enter a 'limp mode' where performance is severely restricted to prevent further damage.
  • In some cases, the vehicle may not start after being turned off, indicating a severe battery issue.

Possible Causes

Most common causes of P0B79 (ordered by frequency):

  1. Faulty battery cells are the most common cause, with a likelihood of about 60%. These cells can wear out over time, leading to voltage irregularities.
  2. Poor electrical connections can cause intermittent issues, and this is the second most common cause at around 25%. Corrosion or loose terminals can prevent proper voltage flow.
  3. The third possible cause involves the hybrid control module malfunctioning, which can misreport battery voltages. Regular maintenance and checks can help prevent this.
  4. Less common but serious causes include physical damage to the battery pack due to accidents or environmental factors.
  5. A rare cause could be software glitches within the vehicle’s onboard systems, requiring a software update from the dealership.

P0B79 Repair Costs

Cost Breakdown by Repair Type

Battery Cell Replacement

Replacing defective cells within the hybrid battery pack.

  • Total: $1,500 - $3,500
  • Success rate: 90%
Hybrid Control Module Replacement

Replacing the hybrid control module if it's determined to be faulty.

  • Total: $800 - $1,500
  • Success rate: 85%
Electrical Connection Repair

Repairing or replacing corroded or loose electrical connections.

  • Total: $100 - $300
  • Success rate: 95%
Money-Saving Tips for P0B79
  • Start with the most common and least expensive repairs first
  • Use GeekOBD APP to confirm diagnosis before replacing expensive parts
  • Consider preventive maintenance to avoid future occurrences
  • Compare prices for OEM vs aftermarket parts based on your needs
  • Address the issue promptly to prevent more expensive secondary damage

Diagnostic Steps

Professional P0B79 Diagnosis Process

Follow these systematic steps to accurately diagnose P0B79. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Start with an initial visual inspection, looking for damaged wiring or loose connections around the hybrid battery and related components (5-10 minutes)

Step 1: Start with an initial visual inspection, looking for damaged wiring or loose connections around the hybrid battery and related components (5-10 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 2: Step 2: Use an OBD2 scan tool, like the GeekOBD APP, to retrieve all codes and freeze-frame data, which will help in understanding the context of the fault (10-15 minutes)

Step 2: Use an OBD2 scan tool, like the GeekOBD APP, to retrieve all codes and freeze-frame data, which will help in understanding the context of the fault (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Conduct component testing on the battery and the hybrid control module using a multimeter to check voltage levels and connectivity (20-30 minutes)

Step 3: Conduct component testing on the battery and the hybrid control module using a multimeter to check voltage levels and connectivity (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: After performing necessary repairs, conduct a system function test to ensure everything is operating correctly and clear the codes (10-15 minutes)

Step 4: After performing necessary repairs, conduct a system function test to ensure everything is operating correctly and clear the codes (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Finally, perform a road test under various conditions to confirm that the repair was successful and the vehicle operates as expected (15-20 minutes)

Step 5: Finally, perform a road test under various conditions to confirm that the repair was successful and the vehicle operates as expected (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

Important Notes

  • Always verify the repair with GeekOBD APP after completing diagnostic steps
  • Clear codes and test drive to ensure the problem is resolved
  • Address underlying causes to prevent code recurrence

Real Repair Case Studies

Case Study 1: Hybrid Battery Replacement in a 2013 Toyota Prius

Vehicle: 2013 Toyota Prius, 85,000 miles

Problem: Customer reported a check engine light and noticeable drop in fuel efficiency.

Diagnosis: After scanning with the GeekOBD APP, DTC P0B79 was confirmed. Voltage tests showed several faulty cells.

Solution: Replaced faulty battery cells and performed a system function test to ensure everything was functioning correctly.

Cost: $2,200 (battery cells $1,800 + labor $400)

Result: Fuel efficiency restored, check engine light cleared, and customer satisfied with the repair.

Case Study 2: Repairing Connections on a 2012 Honda Insight

Vehicle: 2012 Honda Insight, 60,000 miles

Problem: Customer complained of intermittent engine performance and a check engine light.

Diagnosis: Diagnostic scan revealed P0B79; further inspection uncovered corroded battery connections.

Solution: Cleaned and replaced corroded connections, cleared codes, and tested the system.

Cost: $250 (cleaning $50 + new connectors $200)

Result: Vehicle returned to normal operation with improved performance.

Diagnose P0B79

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: P0B79
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes