Some Cadillac CT4 Units Need A Fuel Injector Flow Rate Fix

Certain units of the 2020 through 2023 model year Cadillac CT4 luxury sedan may require a fix to address an issue with the fuel injector flow rate, according to a Service Update issued by Cadillac.

Service Update No. N242450631, which only applies to CT4 models featuring the turbocharged 2.7L I4 engine (production code L3B), states that affected vehicles must be reprogrammed. Essentially, the engine control module (ECM) in affected CT4 units does not sufficiently control fuel injector flow rate in certain driving conditions.

Thankfully, the ECM reprogramming process isn’t expected to take too long, and should be completed in half an hour. This Service Bulletin will expire on September 30^th, 2039.

Cadillac did not disclose how many units of the Cadillac CT4 are affected by this issue. It’s also unclear if the Service Bulletin specifically applies to the CT4 500 Premium Luxury, the Cadillac CT4-V, or both, as both models use the enigne.

As a reminder, under the hood of the Premium Luxury, the L3B engine develops 310 horsepower and 350 pound-feet of torque. These models are identifiable by the 500T badge on the decklid. Under the hood of the CT4-V, that same engine is tuned to deliver a healthy 325 horsepower and 380 pound-feet of torque. Regardless of application, power is routed through the 10-speed automatic transmission. 

Cadillac CT4 units that feature the turbocharged 2.0L I4 engine (production code LSY) are not affected, and neither is the Cadillac CT4-V Blackwing, which harnesses the twin-turbocharged 3.6L V6 engine (production code LGY).

The Cadillac CT4 is produced at the Cadillac Lansing Grand River plant in Michigan, and the luxury sedan rides on the luxury marque’s Alpha 2 platform. Production of the 2025 model year CT4 began on June 3^rd, 2024.