Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2018 Hyundai Sonata Plug-In HybridFACTORY OEM SERVICE PROCEDURE
Repair Procedures: Removal
- Turn ignition switch OFF and disconnect the negative (-) battery terminal.
- Remove the air cleaner assembly and air duct. (Refer to "AIR CLEANER ")
- Shut off the high voltage circuit (Refer to "HIGH VOLTAGE SHUTOFF PROCEDURE ").
- Remove the HPCU. (Refer to "HPCU ")
- Disconnect the TCM connector (A).
- Remove the Hybrid Power Control Unit (HPCU) tray(A).
Tightening torque:
8.8 ~ 13.7 N.m (0.9 ~ 1.4 kgf.m, 6.5 ~ 10.1 lb-ft)
- Remove the TCM(A) after removing the bolt and nut.
TCM installation bolt/nut:
9.8 ~ 11.8 N.m (1.0 ~ 1.2 kgf.m, 7.2 ~ 8.7 lb-ft)
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.