The 2021 Cadillac CT5 luxury sedan is included in a newly issued GM service bulletin because a fix is now available for a software problem in the Engine Control Module that may cause the CT5 to fail to give warning of faults in its catalytic converter.
In some cases, the vehicles’ over-the-air updates may correct the software problem with the ECM without the need for human intervention, but dealerships should still investigate all potentially affected 2021 Cadillac CT5 units.
If the Engine Control Module is not properly recalibrated, the Cadillac CT5 may fail to illuminate the Check Engine light if there is a catalytic converter fault. Additionally, the ECM may fail to generate Diagnostic Trouble Code (DTC) output if the catalytic converter has problems, preventing diagnostic systems from reporting the issue. Finally, it may not diagnose the fault at all.
Only one of the two powerplants available for the 2021 Cadillac CT5 may have this problem. Specifically, the turbocharged 2.0L LSY I4 gasoline engine may have the incorrectly calibrated ECM. The turbocharged 3.0L LGY V6 gasoline engine does not have the noted fault and is not involved in the service bulletin.
The dealership service personnel handling a potentially affected 2021 Cadillac CT5 should first check to see if OTA updates already corrected the problem. Repairs should only proceed if the CT5 is marked as “Open” in the GM Global Warranty Management system’s Investigate Vehicle History screen.
The fix consists of recalibrating the ECM on the affected Cadillac CT5 so that it starts generating DTC codes and illuminating the Check Engine light as normal when a catalytic converter problem occurs. No parts are required for the reprogramming, which takes an average of 30 minutes. CT5 units in inventory should not be sold, delivered, traded, or used for demonstrations until the fix has been applied.
For those who own a 2021 Cadillac CT5 powered by the LSY engine, more information can be obtained or pertinent questions can be asked about the situation by calling the Cadillac customer helpline provided below, referencing the service bulletin’s identifier as needed:
Contacts:
- GM Customer service bulletin number: N232412712
- Cadillac Customer Service: 1-800-333-4223
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Comments
ICE Cadillac cars look nice. GM should put these designers in charge of next gen Malibu. Make the midsize fam car something special to compete w/Accord and K5 styling
I ordered a 2021 CT5 in April of 2021. I never got it. The order was canceled due to Cadillac pushing the V6 and the V8. So there’s probably only a handful of 4 cylinder owners with a 2021. I had to reorder and got a 2022 instead.