2020 Mercedes-Benz GLS450 Service and Repair Manual

This factory service and repair manual for the 2020 Mercedes-Benz GLS450 reflects an engine listed as a mild hybrid: a 3.0L inline-six, turbocharged, DOHC and fueled by gasoline. It powers the four-door sport utility in 4Matic trim, the single body and trim for the year. For a mild hybrid, engine work and electrical work overlap, and the manual meets both with procedures, specifications, torque values, wiring diagrams and diagnostics.

Engines covered

• 3.0L inline-six mild hybrid — DOHC, turbocharged, gasoline

Body styles covered

• 4-door sport utility

Trims covered

• 4Matic

Known issues on the 2020 GLS450. Twenty-two recalls on the federal record name the 2020 GLS450, and owners have lodged 36 complaints, half of them about the electrical system. Among the recalls, the transmission on certain vehicles might not downshift fully in some situations and stall the engine, cured with control unit software; the third-row seatback locks on certain vehicles could give way in a crash; and certain vehicles could have misrouted wiring to the front air bags, which might stop them deploying as designed. Three complaints reported a crash, two an injury and one a fire. Transmission diagnostics, seat procedures and air bag wiring diagrams are covered.