Will I still need a new theft‑deterrent module or BCM?
If the problem is the factory immobilizer, then no—you do not need a new theft‑deterrent module (TDM) or BCM. The PRO Module is designed as a full bypass of the immobilizer function and, when installed correctly on a supported vehicle, it completely takes over the job of telling the engine it’s allowed to run. In cases where the TDM is built into the BCM, EVO or IPC, you still don’t replace that module unless it has additional faults that affect other systems beyond the immobilizer circuit.