OBD Guide
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P1B77

Hybrid/Electric Vehicle Battery 49 Circuit High Voltage

P1B77 is an OBD-II diagnostic trouble code meaning: Hybrid/Electric Vehicle Battery 49 Circuit High Voltage. Common causes: battery management module malfunction, problems with the battery cooling system. Estimated repair cost: $167–889.

Severity
🚨 Critical
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$167–889 (est.)

Symptoms

  • Check engine light comes on
  • Reduced vehicle performance
  • The car goes into emergency mode
  • Disabling the High Voltage System
  • Reduction of electric range

Causes

  • Battery management module malfunction
  • Problems with the battery cooling system
  • Battery cell degradation
  • Short circuit in high voltage circuit
  • Charger fault

How to Fix

  1. High voltage battery diagnostics
  2. Checking the Battery Management System
  3. Battery cell testing
  4. Replacing faulty battery modules
  5. Repairs must only be carried out by a certified hybrid technician.

Related codes

P1B76P1B78P0BBD

FAQ

What does the P1B77 code mean?

P1B77 is an OBD-II diagnostic trouble code that indicates: Hybrid/Electric Vehicle Battery 49 Circuit High Voltage

What causes a P1B77 error code?

The most common causes of P1B77 include: Battery management module malfunction; Problems with the battery cooling system; Battery cell degradation; Short circuit in high voltage circuit.

How do I fix a P1B77 diagnostic trouble code?

To fix P1B77: High voltage battery diagnostics. Checking the Battery Management System. Battery cell testing. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1B77?

Do not drive — repair immediately

How much does it cost to fix P1B77?

The estimated repair cost for P1B77 is $167–889. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat