DIY Hyundai Sonata Hybrid Maintenance

How to Perform DIY Hyundai Sonata Hybrid Maintenance

Some Hyundai Sonata Hybrid Maintenance can be performed by yourself by following this guide.

2011-2014 Hyundai Sonata Hybrid DIY Maintenance Service

The 2011-2014 Hyundai Sonata Hybrid contains a 12-volt battery is located in the trunk on the passenger side. You must remove a cover to access it. The 12-volt battery provides power to all of the standard electronics. If the 12-volt battery is disconnected or dead, the hybrid portion of the system can’t function.

Keep the battery terminals clean; corrosion buildup reduces charging and power and can shorten the life of the battery.

Start by removing the key fob

Remove the proximity key from the vehicle when servicing the vehicle. Keep the key a minimum of six feet away from the vehicle. This will prevent accidental restarting of the vehicle until the 12V battery is disconnected.

Disconnecting the 12-volt battery in a 2011-2014 Hyundai Sonata

Start by removing the IG1 relay from the fuse box under the hood. Then disconnect the 12-volt battery.  Then you can you can remove the service plug on the hybrid battery pack to disconnect it.

How the Hyundai Sonata hybrid works

The Hyundai hybrid uses a motor control unit (MCU) and hybrid control unit (HCU). The MCU and HCU work in conjunction the ECM and TCM. The system has regenerative braking and stop/start features.

The high-voltage battery pack is controlled by the Power Relay Assembly (PRA), with positive and negative main relays, a pre-charge relay, pre-charge resistor, and a battery current sensor. The relays are controlled using power from the 12-volt battery. The PRA is located inside the high-voltage battery pack assembly and controls the high-voltage power circuit between the battery and the HCU.

Hyundai Sonata Lithium battery pack

The Sonata Lithium-ion Polymer HV battery is built with 72 – 3.75V cells wired in series for a nominal voltage of 270V with 5.3 Ah of capacity. The gel electrolyte battery is located behind the rear seat in the trunk area. The battery pack weighs about 93 pounds.

Battery cooling is provided by a blower motor mounted on the battery pack. You’ll find the air intake on the rear package tray under a “speaker grille.” Make sure the intake is never blocked by a coat or packages. In addition, clean the grille regularly if you haul pets in the vehicle. A clogged grille can set a P1BA1 trouble code for a high-voltage battery fan fault. If you have that code, clean the grille and fan. The blower can be serviced or replaced. Also, check the ducting for damage or obstructions.

Hyundai Sonata Hybrid starter

The Hybrid Starter Generator (HSG) is mounted to the front of the engine near the intake manifold. It is belt-driven. It starter/generator cranks the engine for starting and becomes the generator when the HV battery needs charging.

Hyundai Sonata Hybrid AC

the 2011-2014 Hyundai Sonata Hybrid uses and electric AC compressor. The compressor is a 270-volt unit. It uses special non-conductive Polyvinyl Ether (PVE) compressor oil. Never use any other oil!. In fact, if PVE oil ever gets mixed with conventional PAG oil, it can cause decreased volumetric resistivity due to dielectric breakdown. This can permanently damage the electric AC compressor.

Hyundai has multiple software updates

Since this is Hyundai’s first generation hybrid, there are lots of software updates.  Hyundai has been updating software for the hybrid, HVAC and transmission control systems. So always check the calibration and available updates if a customer is experiencing an odd problem.

Refer to the Hyundai maintenance schedules for other service

©, 2022 Rick Muscoplat