OBD Guide
ENFRDEESPT

P0AA5

Hybrid/EV Battery Negative Contactor Circuit Stuck Open

P0AA5 is an OBD-II diagnostic trouble code meaning: Hybrid/EV Battery Negative Contactor Circuit Stuck Open. Common causes: battery negative contactor fault, damage to the contactor control circuit. Estimated repair cost: $167–500.

Severity
🚨 Critical
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$167–500 (est.)

Symptoms

  • Hybrid/electric system does not turn on
  • Reduced power or complete loss of traction
  • Check Engine light comes on
  • Hybrid system error message on dashboard
  • Battery won't charge

Causes

  • Battery negative contactor fault
  • Damage to the contactor control circuit
  • Problems with the hybrid control module (HV ECU)
  • Short circuit or break in the wiring harness
  • Auxiliary 12V battery voltage low

How to Fix

  1. Check the condition of the auxiliary 12V battery
  2. Check the integrity of the contactor control circuit
  3. Test the operation of the negative contactor
  4. Check high voltage fuses
  5. Diagnose the hybrid system control module

Related codes

P0AA6P0AA9P0A80

Error P0AA5 by Vehicle Brand

AcuraAudiBAICBMWBYDBuickCadillacChanganCheryChevroletChryslerCitroenDodgeDongfengExeedFAWFordForthingFotonGACGMGMCGeelyGreat WallHavalHondaHongqiHyundaiInfinitiJACJaecooJaguarJeepJetourKaiyiKiaLadaLexusLi AutoLifanLincolnLivanMazdaMercedes-BenzMercuryMitsubishiNIONissanOldsmobileOmodaOpelPeugeotPlymouthPontiacRenaultSWMSaturnSkodaSkywellSubaruSuzukiTankToyotaVolkswagenVolvoVoyahXPengZeekrZotye

FAQ

What does the P0AA5 code mean?

P0AA5 is an OBD-II diagnostic trouble code that indicates: Hybrid/EV Battery Negative Contactor Circuit Stuck Open

What causes a P0AA5 error code?

The most common causes of P0AA5 include: Battery negative contactor fault; Damage to the contactor control circuit; Problems with the hybrid control module (HV ECU); Short circuit or break in the wiring harness.

How do I fix a P0AA5 diagnostic trouble code?

To fix P0AA5: Check the condition of the auxiliary 12V battery. Check the integrity of the contactor control circuit. Test the operation of the negative contactor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0AA5?

Do not drive — repair immediately

How much does it cost to fix P0AA5?

The estimated repair cost for P0AA5 is $167–500. Actual cost depends on your vehicle, location, and labor rates.

FRDEESPT

See also: Russian version · NationStat