2020 Mercedes-Benz GLS 450 Engine Problems

“We purchased a new 2020 mercedes benz gls 450 in october 2019 from the oakland dealership and shipped the car to hawaii. The vehicle is now 117 months old and has about 4100 miles. Because our vehicle is lightly used we arranged for mercedes benz to supply and installed a 'battery minder' to keep the vehicles 48 volt system charged when we are away for an extended time. However we did not have the battery minder hooked up at this time because we are using the vehicle on a weekly basis. …”

“On numerous occasions, when either slowing down or in a slow turn, the engine dies and will not reengage until I have turned off the vehicle, exited, then reentered an started the vehicle. I have had passengers in the vehicle who will attest to this occurring, in fact, the last time it happened, I was almost broadsided when the vehicle stopped in the middle of a left-hand turn, crossing three lanes of oncoming traffic. The vehicle has been to the dealership at least three times and it's either a software update requirement or we can't duplicate the issue. …”

“While driving, vehicle has abruptly stopped/engine turned off causing car to not accelerate and come to a stop. One instance was on a busy freeway, causing our family to pull off the interstate with nearly no curb, risking rear-end collision due to the abrupt stalling of the vehicle. In this instance, the 48 volt battery failure warning, engine overheat warning, engine light warning came on. When MCB dealership evaluated the vehicle, there were no stored associated error codes and MCB service returned the vehicle to me saying that the issue did not occur when they drove it. …”

“The engine wiring harness insulation near the ignition coil connectors prematurely deteriorated due to prolonged exposure to engine heat in the turbocharger/exhaust area. Multiple wiring connectors exhibited brittle, cracked insulation with exposed conductors. The degraded wiring began shorting within the ignition system, causing engine misfires, ignition circuit faults, and eventual loss of engine operation. …”

“The vehicle is experiencing deterioration of the main engine wiring harness insulation, resulting in exposed wires contacting each other. This condition has caused intermittent check engine lights and electrical fault codes. The dealership has confirmed that the wiring insulation has degraded, allowing wires to contact each other. The issue appears related to material durability of the harness rather than external damage. …”