Engine Control Module (ECM)

The ECM functions in the immobilizer system as a type of slave device. It does not general the password challenge, but it does monitor the challenge and response messages between the BCM and hybrid/EV powertrain control module 1. The ECM will calculate it's own result to the challenge. If the ECM response does not equal the BCM response, the ECM may also disable vehicle propulsion. To allow vehicle propulsion, the response from the BCM, ECM, and hybrid/EV powertrain control module 1 must all match.

The ECM will disable vehicle propulsion if any of the following immobilization conditions occur:

• The start disable password is sent by the BCM.
• No passwords are received. There is no communication with the BCM or hybrid/EV powertrain control module 1.
• The BCM calculated response to the challenge does not equal the calculation performed by the ECM.