P0606 on 2020-2023 Cadillac CT5: Understanding the BCM and ECM Fault
On a 2020-2023 Cadillac CT5, code P0606 often points to a software glitch in the Body Control Module (BCM), not a failed engine computer (ECM). A GM Technical Service Bulletin (TSB) advises a BCM software update as the primary fix. In some cases where the software is already current, the TSB instructs technicians to simply clear the code, making the fix potentially free under warranty.
Most Likely Cause
Body Control Module (BCM) Software Anomaly
Difficulty
1/5
Est. Time
1.5 hrs
DIY Doable?
🔧 Shop
Shop Labor
$100 – $1600
Parts Price
$0 – $1200
Drivable, but...
— You can likely drive to a repair shop, but do so with caution. The TSB notes this code can be accompanied by issues with HVAC and lighting, and any fault with a primary control module carries a risk of unpredictable behavior or other warning messages appearing.
Key Takeaways