OBD Guide
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P1B1A

Hybrid/Electric Vehicle Battery 28 Circuit Low Voltage

P1B1A is an OBD-II diagnostic trouble code meaning: Hybrid/Electric Vehicle Battery 28 Circuit Low Voltage. Common causes: faulty battery cell no. 28, poor contact in battery connections. Estimated repair cost: $56–222.

Severity
🔴 High
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–222 (est.)

Symptoms

  • Reduced vehicle power
  • Increased fuel consumption (for hybrids)
  • Check Engine Light Illuminated
  • Reduced range (for electric vehicles)
  • Unstable operation of the hybrid system

Causes

  • Faulty battery cell No. 28
  • Poor contact in battery connections
  • Wiring harness damage
  • Battery management system (BMS) malfunction
  • Corrosion or oxidation of contacts

How to Fix

  1. Check the voltage of battery cell No. 28
  2. Inspect and clean battery contacts
  3. Check the integrity of the wiring harness
  4. Test the operation of the battery management system (BMS)
  5. If necessary, replace the faulty battery cell

Related codes

P1B1BP1B1CP0AA6

FAQ

What does the P1B1A code mean?

P1B1A is an OBD-II diagnostic trouble code that indicates: Hybrid/Electric Vehicle Battery 28 Circuit Low Voltage

What causes a P1B1A error code?

The most common causes of P1B1A include: Faulty battery cell No. 28; Poor contact in battery connections; Wiring harness damage; Battery management system (BMS) malfunction.

How do I fix a P1B1A diagnostic trouble code?

To fix P1B1A: Check the voltage of battery cell No. 28. Inspect and clean battery contacts. Check the integrity of the wiring harness. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1B1A?

Limited driving only, diagnose soon

How much does it cost to fix P1B1A?

The estimated repair cost for P1B1A is $56–222. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat