2020 Cadillac CT4 Service and Repair Manual

This factory service and repair manual for the 2020 Cadillac CT4 is built around the exact engine and trim on your build sheet, so the torque values, wiring diagrams, and diagnostic steps inside are the ones Cadillac published for this car, covering both the 2.0L L4 (VIN K, LSY) and 2.7L L4 (VIN L, L3B) turbocharged four-cylinders.

Engines covered

• 2.7L inline-four (166 cu in) — DOHC, turbocharged, gasoline
• 2.0L inline-four (122 cu in) — DOHC, turbocharged, gasoline

Body styles covered

• 4-door sedan

Trims covered

• Luxury
• Premium Luxury
• Sport
• V

Known issues on the 2020 CT4. Four recalls are on federal record for this model year. The first covers the roof rail side-curtain air bags, which may not have been installed correctly and can deploy improperly in a crash. The second covers the electronic brake boost system, where sensor connection contamination can interrupt communication with the sensor, requiring extra pedal force to slow and stop the car and raising crash risk. The third covers the daytime running light software, which may fail to deactivate when the headlights are on, producing glare that reduces visibility and raises crash risk. The fourth covers the 10-speed automatic transmission, which can sustain internal damage that locks up the wheels while driving, increasing the risk of a crash. Owners have filed 8 complaints for the year. The factory diagnostic and repair procedures behind each of those systems are here.

From an air bag or brake boost inspection to a DRL software check or transmission diagnosis, it keeps you on the OEM procedure and the correct specification for your specific 2020 CT4.