Diagnostics

OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the vehicle is equipped with the Tire Pressure Monitoring System. If a diagnostics check is needed between e-mails, push an Advisor can run a check., and an Advisor can run a check.

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    Skip Shift (CTS–V)
    Under light acceleration, the transmission will only allow you to shift from 1 (First) to 4 (Fourth). Shifts from 1 (First) to 2 (Second) or 3 (Third) are not allowed. This helps improve fuel ...

    Torque Lock (Automatic Transmission)
    Torque lock is when the weight of the vehicle puts too much force on the parking pawl in the transmission. This happens when parking on a hill and shifting the transmission into P (Park) is ...

    Engine Coolant
    The cooling system in the vehicle is filled with DEX-COOL® engine coolant. This coolant is designed to remain in the vehicle for 5 years or 240 000 km (150,000 mi), whichever occurs first. The fo ...