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P0AC4CriticalHybrid-EV

P0AC4 on 2019-2022 Toyota RAV4 (Hybrid LE, Hybrid XLE, Hybrid XSE, Hybrid Limited, RAV4 Prime) — Hybrid Powertrain Control Module Requested MIL Illumination

1 vehicles · 1 makes

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Most Reported On

2019-2022Toyota RAV4Hybrid LE +4

P0AC4 is an OBD-II diagnostic trouble code meaning “Hybrid Powertrain Control Module Requested MIL Illumination.” The hybrid powertrain control module has requested the malfunction indicator lamp be turned on due to a stored internal/hybrid system fault. This code is most commonly reported on 2019-2022 Toyota RAV4 (Hybrid LE, Hybrid XLE, Hybrid XSE, Hybrid Limited, RAV4 Prime).

On This Page

  • Common Causes
  • Vehicles (1)
  • Related Codes
  • FAQ
  • Sources (3)
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Common Causes

1Internal hybrid powertrain control module fault
2Stored hybrid system DTC requiring MIL
3Communication/wiring fault
4Module power/ground issue

Diagnostic Tools

To diagnose P0AC4, you'll need an OBD-II scanner. Here are our recommendations at every price point.

Budget Pick$10–$20

ANCEL AD310 Classic OBD-II Scanner

by ANCEL

A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).

  • Read & clear engine codes
  • View freeze frame data
  • I/M readiness status
  • No batteries or app needed
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Best Value$90–$120

BlueDriver Pro Bluetooth Scanner

by BlueDriver

Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.

  • Enhanced diagnostics (ABS, SRS, transmission)
  • Repair Reports with verified fixes
  • Smog check readiness
  • Free app (iOS & Android)
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Advanced$180–$230

LAUNCH CRP123X OBD-II Scanner

by LAUNCH

A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

  • Engine, transmission, ABS, SRS diagnostics
  • Live data stream & graphing
  • AutoVIN for vehicle identification
  • Free lifetime updates via Wi-Fi
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Professional$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

by Autel

Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.

  • All-system diagnostics (25+ modules)
  • Bi-directional control & active tests
  • Oil reset, EPB, BMS, TPMS, injector coding
  • 7-inch touchscreen with Android OS
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Vehicles Affected (1)

Toyota P0AC4 page →
RAV4Critical

Hybrid High-Voltage Cable Connector Corrosion Causing Complete Hybrid System Shutdown

2019-2022$0-$7,0000 reports

Related Codes (8)

P0AC0Hybrid Battery Pack Current Sensor "A" Circuit Range/PerformanceP0AC1Hybrid Battery Pack Current Sensor "A" Circuit LowP0AC2Hybrid Battery Pack Current Sensor "A" Circuit HighP0AC3Hybrid Battery Pack Current Sensor "A" Circuit Intermittent/ErraticP0A00Motor Electronics Coolant Temperature Sensor CircuitP0A01Motor Electronics Coolant Temperature Sensor Circuit Range/PerformanceP0A02Motor Electronics Coolant Temperature Sensor Circuit LowP0A03Motor Electronics Coolant Temperature Sensor Circuit High

FAQ

What does P0AC4 mean?

P0AC4 stands for "Hybrid Powertrain Control Module Requested MIL Illumination." The hybrid powertrain control module has requested the malfunction indicator lamp be turned on due to a stored internal/hybrid system fault.

What are the most common causes of P0AC4?

The most common causes of P0AC4 are: Internal hybrid powertrain control module fault, Stored hybrid system DTC requiring MIL, Communication/wiring fault, Module power/ground issue. The specific cause varies by vehicle.

How much does it cost to fix P0AC4?

Repair costs vary widely depending on the root cause and vehicle.

Which vehicles are affected by P0AC4?

Au7o has documented P0AC4 across 1 vehicle models from 1 manufacturers: Toyota.

Sources (3)

  • articleIf You Own A Late-Model Toyota RAV4 Hybrid, Check Your High-Voltage Cables Now - The Autopian
  • articleToyota Hybrid Cable Corrosion Causes Class Action Lawsuit - CarComplaints.com
  • articleCablegate: Class Action Against Toyota is Now Settled - The Car Guide
Get notified about P0AC4 fixes
We add new causes, fixes and affected vehicles for P0AC4 regularly — drop your email and we'll keep you posted. You can also diagnose your own car free.

Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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