Hybrid RAV4 with MIL On and Only ICE Operational
May. 01 2023
May. 01 2023

Vehicle: 2019 Toyota RAV4, 4WD, L4-2.5L (A25A-FXS), Hybrid, Automatic transmission/transaxle

Mileage: 89,366

Problem: This hybrid RAV4 came in with the malfunction indicator light (MIL) on and a hybrid message saying that only the internal combustion engine (ICE) was operational.

RAV4 Hybrid Connector

Case Details: The technician retrieved the following diagnostic trouble codes (DTCs).

  • P0AA6 49 - Hybrid/EV Battery Voltage System Isolation Internal Electronic Failure
  • P1578 00 - Brake System
  • U0155 - Lost Communication with Instrument Panel Cluster (IPC) Control Module
  • U0126 - Lost Communication with Steering Angle Sensor Module

Not sure where to start, the technician called an ALLDATA Tech-Assist consultant who advised deactivating the high-voltage system to inspect the rear differential high-voltage harness connector. He noted that it was quite common to have corrosion in this connector due to its location.

The technician deactivated the high-voltage system and inspected the connector. Sure enough, the connector was completely corroded (see image).

Confirmed Repair: He replaced the complete harness assembly, reset the system and road-tested the vehicle. There were no issues. Another easy fix!

The ALLDATA Tech-Assist team fields cases like this every day. See how Tech-Assist can help your shop save time and money with on-call diagnostic support from ASE-certified Master Technicians. More Tech Tips 

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