OBD Guide

P1A28

Hybrid Battery 1 Voltage High

P1A28 is an OBD-II diagnostic trouble code meaning: Hybrid Battery 1 Voltage High. Common causes: hybrid charging system malfunction, voltage imbalance between battery cells. Estimated repair cost: $167–889.

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

Symptoms

  • Check Engine light comes on
  • Hybrid system power reduction
  • The car goes into emergency mode
  • Unusual sounds from the battery compartment
  • Reduced performance of the hybrid system

Causes

  • Hybrid charging system malfunction
  • Voltage imbalance between battery cells
  • Damage or wear to the hybrid battery
  • Problems with the hybrid system control module
  • Short circuit in high voltage circuit

How to Fix

  1. Diagnostics of the state of the hybrid battery
  2. Checking the charging and cell balancing system
  3. Replacing faulty battery cells
  4. Control Module Software Update
  5. Replacing the hybrid battery if necessary

Related codes

FAQ

What does the P1A28 code mean?

P1A28 is an OBD-II diagnostic trouble code that indicates: Hybrid Battery 1 Voltage High

What causes a P1A28 error code?

The most common causes of P1A28 include: Hybrid charging system malfunction; Voltage imbalance between battery cells; Damage or wear to the hybrid battery; Problems with the hybrid system control module.

How do I fix a P1A28 diagnostic trouble code?

To fix P1A28: Diagnostics of the state of the hybrid battery. Checking the charging and cell balancing system. Replacing faulty battery cells. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1A28?

Do not drive — repair immediately

How much does it cost to fix P1A28?

The estimated repair cost for P1A28 is $167–889. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat