P0AA6 The hybrid computer has detected high voltage leaking to the vehicle body

Hybrid/EV Battery Voltage System Isolation Fault

P0AA6 in short

P0AA6 means the hybrid system detected high voltage leaking to the vehicle body. Common causes are water or corrosion in a high-voltage connector, a chafed orange cable, or coolant inside a motor, inverter or heater. Many hybrids will not restart once it sets. Do not touch any high-voltage parts; have a hybrid technician diagnose it.

A hybrid or electric car's high-voltage system is never connected to the body; it floats. The hybrid computer constantly checks that no current leaks from it to the chassis. P0AA6 sets when it measures that insulation dropping too low, meaning a high-voltage part is shorting to the body somewhere.

Toyota hybrids from 2004 on warn the driver and let the car reach its destination, then refuse to restart. Toyota adds an information code that narrows the area: the A/C compressor, the battery side, the motors and their cables, or the inverter and DC cables. Typical finds are coolant or water inside a part, battery electrolyte, rodent damage, and collision or chafing damage.

Bulletins from other makers point the same way: water in high-voltage connectors (Jeep Wrangler 4xe, RAV4 Hybrid rear motor), a chafed orange harness (Lincoln Aviator and Ford Explorer hybrid), coolant inside the traction motor (Hyundai Ioniq Hybrid), a failed high-voltage water heater (Mazda CX-90 and CX-70 plug-ins), a damaged battery module (Nissan Leaf), and moisture in the battery pack (Chevrolet Volt).

Finding the leak takes an insulation tester on live-rated high-voltage parts. That is work only for a hybrid-trained technician; owners should not open, unplug or probe anything orange.

Most likely causes

  1. Water or corrosion in a high-voltage connector or the battery pack

    Supported by vehicle data
    Why it ranks here
    Toyota, Jeep and GM bulletins and a Lexus owner report all tie P0AA6 to water or corrosion at high-voltage connectors or in the battery pack.
    What would change this
    Rises after heavy rain, deep water, car washes or on a car with known body seal leaks. Falls if the connectors and pack are dry and clean.

  2. Coolant leaking inside a motor, inverter or high-voltage heater

    Supported by vehicle data
    Why it ranks here
    Hyundai (traction motor coolant leak) and Mazda (high-voltage water heater) bulletins list P0AA6, and the Toyota guide names coolant in the inverter.
    What would change this
    Rises if coolant level drops or the cabin heater stops working. Falls if the cooling system holds level and the fault is isolated elsewhere.

  3. Chafed or damaged orange high-voltage cable

    Supported by vehicle data
    Why it ranks here
    Ford's bulletin for the Aviator and Explorer hybrid traces P0AA6 to a clamp chafing the high-voltage harness; the Toyota guide lists collision and rodent damage.
    What would change this
    Rises after underbody damage, a collision or signs of rodents. Falls if the harness is intact.

  4. Insulation failure in a drive motor or the A/C compressor

    Possible — needs testing
    Why it ranks here
    Toyota's guide lists the motor windings and the electric A/C compressor as isolation fault locations, and one Prius owner reports a transaxle replacement for it. These need insulation testing to confirm.
    What would change this
    Rises if the fault appears only with the A/C on or the information code points to the motor. Falls if the leak is traced to wiring or the battery.
    How to test the hybrid drive motor

  5. Damaged battery module inside the pack

    Supported by vehicle data
    Why it ranks here
    Nissan's bulletin for the 2019–2025 Leaf ties a no-start with P0AA6 to a battery module with a bent retention plate; the Toyota guide lists battery electrolyte leaks.
    What would change this
    Rises on a Leaf with P31E7, or if the fault is isolated to the battery side. Falls if the battery side tests good.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes with a scan tool and note any information or sub-codes, dashboard messages, and whether it happened in rain or with the A/C on. Do not open, unplug or touch anything orange.

    Low riskTool: OBD-II scan tool

    • IfThe vehicle has a bulletin for P0AA6 (RAV4 Hybrid, Leaf, Volt, Aviator, Explorer hybrid, Wrangler 4xe, Ioniq Hybrid, CX-90 or CX-70 plug-in)

      It meansA known cause exists for this model.

      Go to step 2

    • IfToyota or Lexus with an information code

      It meansThe information code narrows down the area for the technician.

      Go to step 3

    • IfAny other vehicle

      It meansIt needs a hybrid technician's insulation testing.

      Go to step 3

  2. Give the VIN to a dealer and ask which P0AA6 bulletins, inspections or warranty extensions apply.

    Low riskTool: VIN lookup at a dealer

    • IfA bulletin applies

      It meansThe dealer inspects the named area first.

      Go to step 3

    • IfNothing applies

      It meansThe leak has to be found by testing.

      Go to step 3

  3. Have a dealer or hybrid-trained technician make the system safe and use an insulation tester to find where high voltage is leaking to the body.

    Best left to a shopTool: insulation tester (megohmmeter) and high-voltage safety equipment

    Warning:High voltage: the battery pack, inverter, motors and orange cables carry hundreds of volts that can kill. Do not unplug, probe or touch them. This work needs a hybrid-trained technician who makes the system safe first. With an isolation fault, high voltage may already be reaching the body.

Symptoms

  • Check engine light and hybrid system warning
  • Car will not restart after being shut off
  • Car will not charge (plug-ins)
  • Fault appears after rain, a car wash or driving through water
  • "Stop Safely Now" warning Gets more serious: stop and have it checked.
  • Reduced power while driving Gets more serious: stop and have it checked.

How to fix

This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.

Parts and cost context

  • High voltage harness, connectors, motor, inverter, heater or battery module:The part replaced depends on where the leak is found; all of them are high-voltage dealer work. Labor varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Toyota

  • 2004–2015 · Prius

    Supported by vehicle data

    Toyota hybrids block restarting after P0AA6 and add an information code naming the area. Owners report no-starts; one 2007 Prius needed a transaxle.

  • 2019–2021 · RAV4

    Supported by vehicle data

    RAV4 Hybrid: corrosion at the rear motor high-voltage connector.

  • TSB-0026-22Status unverified

    P0AA649/P1C8049 from corrosion at the rear motor connector

    2019–2021rav4 · issued · NHTSA 10214334

    Corrosion or dirt at high-voltage connector Y6 at the rear motor generator (RAV4 Hybrid).

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • 017-05Status unverified

    MIL on with P0AA6 or P3009, information codes 526 and 614

    2004–2005prius · issued · NHTSA 10018850

    Title-only summary.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Nissan

  • NTB23-024AStatus unverified

    Vehicle will not start with P31E7 and P0AA6

    2019–2025leaf · issued · NHTSA 11004974

    Inspect the battery module for a bent retention plate and replace it if needed.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Chevrolet

  • PIC5920DStatus unverified

    Vehicle will not charge, P0AA6

    2011–2014volt · issued · NHTSA 10112220

    Inspect the battery pack drain plug for moisture; then update module software.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Lincoln

  • 2020–2023 · Aviator

    Supported by vehicle data

    "Stop safely now" warning with P0AA6 from a chafed high-voltage harness; the same bulletin covers the Ford Explorer 3.0L hybrid.

  • SSM 51701Status unverified

    Stop safely now warning with P0AA6

    2020–2023aviator · issued · NHTSA 10237795

    Clamp chafing the orange high-voltage harness near the charge air cooler pipe (also Ford Explorer 3.0L hybrid).

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Jeep

  • 08-131-21Status unverified

    Water intrusion at P1/P2 high-voltage connectors

    2021wrangler · issued · NHTSA 10218554

    No start; replace the connector seals if needed.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Hyundai

  • 5NP-B7W2G-12Status unverified

    Internal coolant leak in the traction motor

    2017ioniq · issued · NHTSA 10125162

    P0AA6 with possible reduced power and inoperative A/C (Ioniq Hybrid).

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Mazda

  • SSP D9Status unverified

    High-voltage water heater warranty extension

    2024–2025cx-90, cx-70 · issued · NHTSA 11022765

    Heater wire break or low insulation resistance sets P0AA6:00; coverage extended to 8 years.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

No curated relationships for P0AA6 yet.

All Hybrid and electric drive codes

P0AA6 questions

Is it safe to drive with P0AA6?

Many hybrids let you finish the trip but will not restart afterwards. Head straight to a dealer or safe place, and stop if a "Stop Safely" warning appears or power drops.

Can I fix P0AA6 myself?

No. Finding the leak means testing high-voltage parts with an insulation tester, and high voltage may already be reaching the body. It needs a hybrid-trained technician.

Can rain or a car wash cause P0AA6?

Yes. Several bulletins trace it to water or corrosion in high-voltage connectors, and one Lexus owner reports water entering through cracked body seams.

Sources and review

  1. Diagnosing Toyota High Voltage Ground Isolation Faults — ToyotaTech (AutomotiveTechInfo.com), Paul Cortes, November 2021 ,
  2. Vehicle will not start with P31E7 and P0AA6, Nissan Leaf (NTB23-024A) — Nissan North America / NHTSA ,
  3. Vehicle will not charge, loss of isolation with P0AA6, Volt and ELR (Preliminary Information PIC5920D) — General Motors / NHTSA ,
  4. Stop safely now warning with P0AA6 from a chafed high-voltage harness, 2020–2023 Aviator/Explorer hybrid (SSM 51701) — Ford Motor Company / NHTSA ,
  5. Internal coolant leak in the traction motor, 2017 Ioniq Hybrid (bulletin 5NP-B7W2G-12) — Hyundai Motor America / NHTSA ,
  6. P0AA649/P1C8049 from corrosion at the rear motor high-voltage connector, 2019–2021 RAV4 Hybrid (TSB-0026-22) — Toyota Motor Sales / NHTSA ,
  7. Possible water intrusion at the P1 and P2 high-voltage connectors, 2021 Wrangler 4xe (bulletin 08-131-21) — FCA US LLC / NHTSA ,
  8. Owner complaints: Toyota and Lexus hybrids with P0AA6 — NHTSA Office of Defects Investigation
  9. Water heater malfunction warranty extension SSP D9, 2024 CX-90 PHEV and 2025 CX-70 PHEV — Mazda North American Operations / NHTSA ,
  10. Maintenance and Safety of Electric Vehicles — Alternative Fuels Data Center, U.S. Department of Energy
  11. MIL on with P0AA6 or P3009, information codes 526 and 614 (bulletin 017-05) — Toyota Motor Sales / NHTSA ,
Last reviewed
Written by
Saurabh K.
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